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268 lines
7.7 KiB
268 lines
7.7 KiB
/*****************************************************************************
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* nit.h: ETSI EN 300 468 Network Information Table (NIT)
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*****************************************************************************
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* Copyright (C) 2009-2010 VideoLAN
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*
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* Authors: Christophe Massiot <massiot@via.ecp.fr>
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject
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* to the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
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* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
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* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*****************************************************************************/
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/*
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* Normative references:
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* - ETSI EN 300 468 V1.11.1 (2010-04) (SI in DVB systems)
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*/
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#ifndef __BITSTREAM_DVB_NIT_H__
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#define __BITSTREAM_DVB_NIT_H__
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#include <bitstream/common.h>
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#include <bitstream/mpeg/psi/psi.h>
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#include <bitstream/mpeg/psi/descriptors.h>
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#ifdef __cplusplus
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extern "C"
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{
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#endif
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/*****************************************************************************
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* Network Information Table
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*****************************************************************************/
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#define NIT_PID 0x10
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#define NIT_TABLE_ID_ACTUAL 0x40
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#define NIT_TABLE_ID_OTHER 0x41
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#define NIT_HEADER_SIZE (PSI_HEADER_SIZE_SYNTAX1 + 2)
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#define NIT_HEADER2_SIZE 2
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#define NIT_TS_SIZE 6
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#define nit_set_nid psi_set_tableidext
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#define nit_get_nid psi_get_tableidext
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static inline void nit_init(uint8_t *p_nit, bool b_actual)
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{
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psi_init(p_nit, true);
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psi_set_tableid(p_nit, b_actual ? NIT_TABLE_ID_ACTUAL : NIT_TABLE_ID_OTHER);
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p_nit[8] = 0xf0;
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}
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static inline void nit_set_length(uint8_t *p_nit, uint16_t i_nit_length)
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{
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psi_set_length(p_nit, NIT_HEADER_SIZE + PSI_CRC_SIZE - PSI_HEADER_SIZE
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+ i_nit_length);
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}
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static inline void nit_set_desclength(uint8_t *p_nit, uint16_t i_length)
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{
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p_nit[8] &= ~0xf;
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p_nit[8] |= i_length >> 8;
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p_nit[9] = i_length & 0xff;
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}
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static inline uint16_t nit_get_desclength(const uint8_t *p_nit)
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{
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return ((p_nit[8] & 0xf) << 8) | p_nit[9];
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}
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static inline uint8_t *nit_get_descs(uint8_t *p_nit)
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{
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return &p_nit[8];
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}
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static inline void nith_init(uint8_t *p_nit_h)
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{
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p_nit_h[0] = 0xf0;
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}
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static inline void nith_set_tslength(uint8_t *p_nit_h, uint16_t i_length)
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{
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p_nit_h[0] &= ~0xf;
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p_nit_h[0] |= i_length >> 8;
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p_nit_h[1] = i_length & 0xff;
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}
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static inline uint16_t nith_get_tslength(const uint8_t *p_nit_h)
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{
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return ((p_nit_h[0] & 0xf) << 8) | p_nit_h[1];
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}
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static inline void nitn_init(uint8_t *p_nit_n)
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{
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p_nit_n[4] = 0xf0;
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}
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static inline void nitn_set_tsid(uint8_t *p_nit_n, uint16_t i_tsid)
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{
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p_nit_n[0] = i_tsid >> 8;
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p_nit_n[1] = i_tsid & 0xff;
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}
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static inline uint16_t nitn_get_tsid(const uint8_t *p_nit_n)
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{
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return (p_nit_n[0] << 8) | p_nit_n[1];
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}
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static inline void nitn_set_onid(uint8_t *p_nit_n, uint16_t i_onid)
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{
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p_nit_n[2] = i_onid >> 8;
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p_nit_n[3] = i_onid & 0xff;
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}
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static inline uint16_t nitn_get_onid(const uint8_t *p_nit_n)
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{
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return (p_nit_n[2] << 8) | p_nit_n[3];
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}
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static inline void nitn_set_desclength(uint8_t *p_nit_n, uint16_t i_length)
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{
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p_nit_n[4] &= ~0xf;
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p_nit_n[4] |= i_length >> 8;
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p_nit_n[5] = i_length & 0xff;
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}
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static inline uint16_t nitn_get_desclength(const uint8_t *p_nit_n)
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{
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return ((p_nit_n[4] & 0xf) << 8) | p_nit_n[5];
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}
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static inline uint8_t *nitn_get_descs(uint8_t *p_nit_n)
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{
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return &p_nit_n[4];
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}
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static inline uint8_t *nit_get_header2(uint8_t *p_nit)
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{
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return p_nit + NIT_HEADER_SIZE + nit_get_desclength(p_nit);
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}
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static inline uint8_t *nit_get_ts(uint8_t *p_nit, uint8_t n)
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{
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uint16_t i_section_size = psi_get_length(p_nit) + PSI_HEADER_SIZE
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- PSI_CRC_SIZE;
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uint8_t *p_nit_n = p_nit + NIT_HEADER_SIZE + nit_get_desclength(p_nit)
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+ NIT_HEADER2_SIZE;
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if (p_nit_n - p_nit > i_section_size) return NULL;
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while (n) {
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if (p_nit_n + NIT_TS_SIZE - p_nit > i_section_size) return NULL;
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p_nit_n += NIT_TS_SIZE + nitn_get_desclength(p_nit_n);
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n--;
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}
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if (p_nit_n - p_nit >= i_section_size) return NULL;
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return p_nit_n;
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}
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static inline bool nit_validate_ts(const uint8_t *p_nit, const uint8_t *p_nit_n,
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uint16_t i_desclength)
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{
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uint16_t i_section_size = psi_get_length(p_nit) + PSI_HEADER_SIZE
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- PSI_CRC_SIZE;
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return (p_nit_n + NIT_TS_SIZE + i_desclength
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<= p_nit + i_section_size);
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}
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static inline bool nit_validate(const uint8_t *p_nit)
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{
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uint16_t i_section_size = psi_get_length(p_nit) + PSI_HEADER_SIZE
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- PSI_CRC_SIZE;
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const uint8_t *p_nit_n;
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if (!psi_get_syntax(p_nit)
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|| (psi_get_tableid(p_nit) != NIT_TABLE_ID_ACTUAL
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&& psi_get_tableid(p_nit) != NIT_TABLE_ID_OTHER))
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return false;
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if (i_section_size < NIT_HEADER_SIZE
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|| i_section_size < NIT_HEADER_SIZE + nit_get_desclength(p_nit))
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return false;
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if (!descs_validate(p_nit + 8))
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return false;
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p_nit_n = p_nit + NIT_HEADER_SIZE + nit_get_desclength(p_nit);
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if (nith_get_tslength(p_nit_n) != p_nit + i_section_size - p_nit_n
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- NIT_HEADER2_SIZE)
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return false;
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p_nit_n += NIT_HEADER2_SIZE;
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while (p_nit_n + NIT_TS_SIZE - p_nit <= i_section_size
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&& p_nit_n + NIT_TS_SIZE + nitn_get_desclength(p_nit_n) - p_nit
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<= i_section_size) {
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if (!descs_validate(p_nit_n + 4))
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return false;
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p_nit_n += NIT_TS_SIZE + nitn_get_desclength(p_nit_n);
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}
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return (p_nit_n - p_nit == i_section_size);
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}
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static inline uint8_t *nit_table_find_ts(uint8_t **pp_sections,
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uint16_t i_tsid, uint16_t i_onid)
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{
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uint8_t i_last_section = psi_table_get_lastsection(pp_sections);
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uint8_t i;
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for (i = 0; i <= i_last_section; i++) {
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uint8_t *p_section = psi_table_get_section(pp_sections, i);
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uint8_t *p_ts;
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int j = 0;
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while ((p_ts = nit_get_ts(p_section, j)) != NULL) {
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j++;
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if (nitn_get_tsid(p_ts) == i_tsid && nitn_get_onid(p_ts) == i_onid)
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return p_ts;
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}
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}
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return NULL;
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}
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static inline bool nit_table_validate(uint8_t **pp_sections)
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{
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uint8_t i_last_section = psi_table_get_lastsection(pp_sections);
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uint8_t i;
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for (i = 0; i <= i_last_section; i++) {
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uint8_t *p_section = psi_table_get_section(pp_sections, i);
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uint8_t *p_ts;
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int j = 0;
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if (!psi_check_crc(p_section))
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return false;
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while ((p_ts = nit_get_ts(p_section, j)) != NULL) {
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j++;
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/* check that the TS is not already in the table */
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if (nit_table_find_ts(pp_sections, nitn_get_tsid(p_ts),
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nitn_get_onid(p_ts)) != p_ts)
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return false;
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}
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}
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return true;
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}
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#ifdef __cplusplus
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}
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#endif
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#endif
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