epgdump/bit.c

   1 // -*- tab-width:4 -*-
   2
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6
   7 #include "bit.h"
   8
   9 // 2-STD-B10v4_6.pdf p89 (101/399)
  10 int parseBIThead(unsigned char *data, BIThead *head) {
  11         int boff = 0;
  12
  13         memset(head, 0, sizeof(BIThead));
  14
  15         head->table_id = getBit(data, &boff, 8);
  16         head->section_syntax_indicator = getBit(data, &boff, 1);
  17         head->reserved_future_use1 = getBit(data, &boff, 1);
  18         head->reserved1 = getBit(data, &boff, 2);
  19         head->section_length = getBit(data, &boff, 12);
  20         head->original_network_id = getBit(data, &boff, 16);
  21         head->reserved2 = getBit(data, &boff, 2);
  22         head->version_number = getBit(data, &boff, 5);
  23         head->current_next_indicator = getBit(data, &boff, 1);
  24         head->section_number = getBit(data, &boff, 8);
  25         head->last_section_number = getBit(data, &boff, 8);
  26         head->reserved_future_use2 = getBit(data, &boff, 3);
  27         head->broadcast_view_propriety = getBit(data, &boff, 1);
  28         head->first_descriptors_length = getBit(data, &boff, 12);
  29         return 10 + head->first_descriptors_length;
  30 }
  31
  32 // 4-TR-B14v4_3-2p3.pdf p4-254 (276/543)
  33 int parseBITloop(unsigned char *data, BITloop *loop) {
  34         int boff = 0;
  35
  36         memset(loop, 0, sizeof(BITloop));
  37
  38         loop->broadcaster_id = getBit(data, &boff, 8);
  39         loop->reserved_future_use = getBit(data, &boff, 4);
  40         loop->broadcaster_descriptors_length = getBit(data, &boff, 12);
  41
  42         return 3;
  43 }
  44
  45 // SI伝送パラメータ記述子
  46 int parseBITdesc(unsigned char *data, BITdesc *desc) {
  47         int boff = 0;
  48
  49         memset(desc, 0, sizeof(BITdesc));
  50
  51         desc->descriptor_tag = getBit(data, &boff, 8);
  52         desc->descriptor_length = getBit(data, &boff, 8);
  53         desc->parameter_version = getBit(data, &boff, 8);
  54         desc->update_time = getBit(data, &boff,16);
  55
  56         return 5;
  57 }
  58
  59 int parseBITtable(unsigned char *data, BITtable *table) {
  60         int boff = 0;
  61
  62         memset(table, 0, sizeof(BITtable));
  63
  64         table->table_id = getBit(data, &boff, 8);
  65         table->table_description_length = getBit(data, &boff, 8);
  66         table->table_cycle = getBit(data, &boff, 16);
  67
  68         return table->table_description_length + 2;
  69 }
  70
  71 void dumpBIT(unsigned char *ptr)
  72 {
  73         BIThead   bith;
  74         BITloop   bitl;
  75         BITdesc   bitd;
  76         BITtable  bitt;
  77
  78         int len = 0;
  79         int loop_len = 0;
  80         int desc_len = 0;
  81         int table_len = 0;
  82
  83         /* BIT */
  84         len = parseBIThead(ptr, &bith);
  85         ptr += len;
  86         loop_len = bith.section_length - (len - 3 + 4); // 3は共通ヘッダ長 4はCRC
  87
  88         while(loop_len > 0) {
  89                 len = parseBITloop(ptr, &bitl);
  90                 ptr += len;
  91                 loop_len -= len;
  92
  93                 desc_len = bitl.broadcaster_descriptors_length;
  94                 loop_len -= desc_len;
  95
  96                 while(desc_len > 0) {
  97                         len = parseBITdesc(ptr, &bitd);
  98                         ptr += len;
  99                         desc_len -= len;
 100
 101                         table_len = bitd.descriptor_length - 3;
 102                         desc_len -= table_len;
 103
 104                         if ( bitd.descriptor_tag != 0xD7 ) {
 105                                 ptr += table_len;
 106                                 continue;
 107                         }
 108
 109                         while(table_len > 0) {
 110                                 len = parseBITtable(ptr, &bitt);
 111                                 ptr += len;
 112                                 table_len -= len;
 113
 114                                 /*
 115                                         0x4E (M-EIT,L-EIT)
 116                                         0x50(各局伝送パラメータ運用部分の H-EIT[schedule basic])
 117                                         0x58 (各局伝送パラメータ運用部分の H-EIT[schedule extended])
 118                                         0xC3(SDTT)
 119                                         0xC8(CDT)
 120                                 */
 121
 122                                 if (0) printf("BIT=(%d)%d:%d:%d:%d|0x%x:%d:%d=BCD(%d)\n",
 123                                         bitl.broadcaster_id, bitd.descriptor_tag, bitd.descriptor_length,
 124                                         bitd.parameter_version, bitd.update_time,
 125                                         bitt.table_id, bitt.table_description_length,
 126                                         bitt.table_cycle, BCD(bitt.table_cycle));
 127                         }
 128                 }
 129         }
 130
 131         return;
 132 }
 133