from: http://blog.csdn.net/xioahw/article/details/4093488

PAT表格定義如下：

typedef struct TS_PAT_Program
{
?unsigned program_number????:16;?//節目號
?unsigned program_map_PID???:13;?? //節目映射表的PID，節目號大于0時對應的PID，每個節目對應一個
}TS_PAT_Program;

//PAT表結構體
typedef struct TS_PAT
{
??? unsigned table_id??????????????????????? : 8; //固定為0x00 ，標志是該表是PAT
??? unsigned section_syntax_indicator??????? : 1; //段語法標志位，固定為1
??? unsigned zero??????????????????????????? : 1; //0
??? unsigned reserved_1??????????????????????? : 2; // 保留位
??? unsigned section_length??????????????????? : 12; //表示這個字節后面有用的字節數，包括CRC32
??? unsigned transport_stream_id??????????? : 16; //該傳輸流的ID，區別于一個網絡中其它多路復用的流
??? unsigned reserved_2??????????????????????? : 2;// 保留位
??? unsigned version_number??????????????????? : 5; //范圍0-31，表示PAT的版本號
??? unsigned current_next_indicator??????????? : 1; //發送的PAT是當前有效還是下一個PAT有效
??? unsigned section_number??????????????????? : 8; //分段的號碼。PAT可能分為多段傳輸，第一段為00，以后每個分段加1，最多可能有256個分段
??? unsigned last_section_number??????????? : 8;? //最后一個分段的號碼
?
?std::vector<TS_PAT_Program> program;
??? unsigned reserved_3??????????????????????? : 3; // 保留位
??? unsigned network_PID??????????????????? : 13; //網絡信息表（NIT）的PID,節目號為0時對應的PID為network_PID

??? unsigned CRC_32??????????????????????????? : 32;? //CRC32校驗碼
} TS_PAT;

?

解析代碼如下：

HRESULT CTS_Stream_Parse::adjust_PAT_table( TS_PAT * packet, unsigned char * buffer)
{
??? packet->table_id??????????????????? = buffer[0];
??? packet->section_syntax_indicator??? = buffer[1] >> 7;
??? packet->zero??????????????????????? = buffer[1] >> 6 & 0x1;
??? packet->reserved_1??????????????????? = buffer[1] >> 4 & 0x3;
??? packet->section_length??????????????? = (buffer[1] & 0x0F) << 8 | buffer[2];
?
??? packet->transport_stream_id??????????? = buffer[3] << 8 | buffer[4];
?
??? packet->reserved_2??????????????????? = buffer[5] >> 6;
??? packet->version_number??????????????? = buffer[5] >> 1 &? 0x1F;
??? packet->current_next_indicator??????? = (buffer[5] << 7) >> 7;
??? packet->section_number??????????????? = buffer[6];
??? packet->last_section_number??????????? = buffer[7];

??? int len = 0;
??? len = 3 + packet->section_length;
??? packet->CRC_32??????????????????????? = (buffer[len-4] & 0x000000FF) << 24
??| (buffer[len-3] & 0x000000FF) << 16
??| (buffer[len-2] & 0x000000FF) << 8
??| (buffer[len-1] & 0x000000FF);
?
??
?int n = 0;
??? for ( n = 0; n < packet->section_length - 12; n += 4 )
??? {
??unsigned? program_num = buffer[8 + n ] << 8 | buffer[9 + n ];??
??????? packet->reserved_3??????????????? = buffer[10 + n ] >> 5;
??
??packet->network_PID = 0x00;
??if ( program_num == 0x00)
??{??
??????????? packet->network_PID = (buffer[10 + n ] & 0x1F) << 8 | buffer[11 + n ];

???TS_network_Pid = packet->network_PID; //記錄該TS流的網絡PID

???TRACE(" packet->network_PID %0x /n/n", packet->network_PID );
??}
??????? else
??????? {
???TS_PAT_Program PAT_program;
???PAT_program.program_map_PID = (buffer[10 + n] & 0x1F) << 8 | buffer[11 + n];
???PAT_program.program_number = program_num;
???packet->program.push_back( PAT_program );
???
???TS_program.push_back( PAT_program );//向全局PAT節目數組中添加PAT節目信息?????
??????? } ???????
??? }
?return 0;
}

因此，PAT數據解析結果如下：

PAT數據

table_id????：0x00????????????????????????????//8 ?
section_syntax_indicator???：0x01???????????// 1
'0'??????????????：0x00?????????????????????? // 1
reserved?????????????0x03????????????????// 2
section_length??????：0x00d????????????????????// 12
transport_stream_id????：0x0000???????????????? // 16
reserved????????????????????????：0x03????????// 2
version_number????????????：0x00??????????????// 5
current_next_indicator???：0x01???????????????// 1
section_number??????????????：0x00????????????// 8
last_section_number?????????：0x00??????????? // 8
program_number?????：0x0001??????????????????? // 16
??reserved????????????????：0x07?????????????? // 3
program_map_PID??????：0x03e8???????????? // 13
CRC???????? ：0x f0 0b d7 79

由解析結構可知，該PAT表格中沒有網絡信息包信息，只包含一個節目，其PID為0x03e8

總結

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