简单解析PAT、PMT的程序

刚开始学习有关TS、PAT、PMT方面的内容，参考了别人的一些程序，然后写了一个简单的解析TS的小程序。如果有地方错误，请发邮件给我843036544@qq.com。

#include<stdio.h>

#include<stdlib.h>
#include<string.h>

#define ts_path "/home/huohuo/huangwork/work/birds.ts" //TS文件的绝对路径

void Read_Ts_Packet(FILE *file_handle,unsigned char *packet_buf,int len); //读一个TS流的packet
int parse_TS(unsigned char *buffer,int FileSize); //分析TS流，并找出PAT的PID和PAT的table
void parse_PAT(unsigned char *buffer,int len); //分析PAT，并找出所含频道的数目和PMT的PID
void pronum_pmtid_printf(); //打印PMT的PID
unsigned char* Find_PMT(unsigned short pmt_pid); //找出PMT的table
void parse_PMT(unsigned char *buffer,int len,unsigned short pmt_pid); //解析PMT，找出其中的Video和Audio的PID
void printf_program_list(); //打印PMT table中包含的stream的类型和PID
unsigned char* Find_video_audio(unsigned short program_pid,unsigned char type); //找出Video或者Audio的table
typedef struct
{
unsigned short program_num; //program's num
unsigned short pmt_pid; //
}PROGRAM;

typedef struct
{
unsigned char stream_type;
unsigned short elementary_pid;
}PRO_LIST;

PROGRAM programs[10] = {{0,0}}; //用来存储PMT的PID和数量
unsigned int num = 0; //total program

PRO_LIST program_list[10] = {{0,0}}; //用来存储PMT中stream的类型和PID
unsigned int program_list_num = 0;
FILE *file_handle; //指向TS流的指针
unsigned int FileSize = 0;

int main()
{

unsigned char buffer[188] = {0};
unsigned char *pmt_buffer, *Video_or_Audio_buffer;
unsigned int i=0,j=0,ret=0;

pmt_buffer = (unsigned char*)malloc(sizeof(char)*188); //给buffer分配空间
memset(pmt_buffer,0,sizeof(char)*188); //清空buffer

Video_or_Audio_buffer = (unsigned char*)malloc(sizeof(char)*188);
memset(Video_or_Audio_buffer,0,sizeof(char)*188);

file_handle = fopen(ts_path,"rb+"); //以二进制方式打开TS文件

if(NULL == file_handle) //判断是否打开文件
{
perror("fopen");
printf("open file error!\n");
return 0;
}

else
printf("open file success!\n");

fseek(file_handle,0,SEEK_END); //指针file_handle将以SEEK_END位置偏移0个位置，即将指针移动到文件尾
FileSize = ftell(file_handle); // 计算file_handle到文件头的偏移字节数，即计算文件的大小

printf("file size = %d\n",FileSize);

rewind(file_handle); // equivalent (void) feek(file_handle,0L,SEEK_SET) 将file_handle指针移动到文件头位置

printf("find PAT begin-------->\n");

for(i=0;i<FileSize/188;i++)
{
Read_Ts_Packet(file_handle,buffer,188); //读TS的packet函数，每次读188个字节到buffer
ret = parse_TS(buffer,188); //解析188个字节的TS's packet，并打印找到的PAT’s table。如果解析成功即找到PAT，则返回 1，否则返回0

if(ret == 1)
{
break;
}
else
{
printf("There is no PAT table!\n");
}
}

if(ret == 1)
{
parse_PAT(buffer,188); //解析PAT，并找出所含频道的数目和PMT的PID
}

pronum_pmtid_printf(); //打印PMT的PID
rewind(file_handle);
printf("find PMT begin -------->\n");
for(i=0;i<num;i++)
{
pmt_buffer = Find_PMT(programs[i].pmt_pid); //根据PMT的PID找到PMT's table

printf("PMT table -------->\n");
for(j=0;j<188;j++)
{
printf("0x%x ",pmt_buffer[j]); //打印PMT
}

if(pmt_buffer)
{
parse_PMT(pmt_buffer,188,programs[i].pmt_pid); //解析找到的PMT，得到Video、Audio等的PID
}
memset(pmt_buffer,0,sizeof(char)*188);

printf("\n");
}

printf_program_list(); //打印elementary流的PID和type。
rewind(file_handle);

printf("find Audio and Video begin-------->\n");
for(i=0;i<program_list_num;i++)
{
Video_or_Audio_buffer = Find_video_audio(program_list[i].elementary_pid,
program_list[i].stream_type); //根据PID找到elementary流

printf("the program's PID is 0x%x\n",program_list[i].elementary_pid);
printf("the program's Table --------->\n");
for(j=0;j<188;j++)
{
printf("0x%x ",Video_or_Audio_buffer[j]); //打印elementary's table
}
memset(Video_or_Audio_buffer,0,sizeof(char)*188);
printf("\n");

}

free(pmt_buffer);
free(Video_or_Audio_buffer);
pmt_buffer = NULL;
Video_or_Audio_buffer = NULL;

fclose(file_handle);
printf("\n");

return 1;

}

/**************************************************
* read one TS packet's data
* *************************************************/
void Read_Ts_Packet(FILE *file_handle,unsigned char *packet_buf,int len)
{
fread(packet_buf,188,1,file_handle);
}

int parse_TS(unsigned char *buffer,int FileSize)
{
unsigned char *temp = buffer;
short pat_pid;
int i = 0;

if(buffer[0] != 0x47)
{
printf("it's not a ts packet!\n");
return 0;
}

while(temp < buffer + FileSize)
{
pat_pid = (temp[1] & 0x1f)<<8 | temp[2];

if(pat_pid != 0)
printf("finding PAT table ....\n");
else
{
printf("already find the PAT table\n");
printf("pat_pid = 0x%x\n",pat_pid);
printf("pat table ------->\n");
for(i=0;i<=187;i++)
{
printf("0x%x ",buffer[i]);
}
printf("\n");
return 1;
}

temp = temp + 188;

}

return 0;
}

/*******************************************************
* parse PAT table, get the PMT's PID
* ********************************************************/
void parse_PAT(unsigned char *buffer,int len)
{

unsigned char *temp, *p;
char adaptation_control;
int adaptation_length,i=0;
unsigned short section_length,prg_No,PMT_Pid;

temp = buffer;
adaptation_control = temp[3] & 0x30;

if(adaptation_control == 0x10)
temp = buffer + 4 + 1;

else if (adaptation_control == 0x30)
{
adaptation_length = buffer[4];
temp = buffer + 4 + 1 +adaptation_length + 1;

}

else
{
return ;
}

section_length = (temp[1]&0x0f)<<8 | temp[2];

p = temp + 1 +section_length;
temp = temp + 8;

while(temp < p - 4)
{
prg_No = (temp[0]<<8) | (temp[1]);

if(prg_No == 0)
{
temp = temp + 4;
continue;
}

else
{
PMT_Pid = (temp[2]&0x1f)<<8 | temp[3];

programs[num].program_num = prg_No;
programs[num].pmt_pid = PMT_Pid;
// printf("pmt_pid is ox%x\n", PMT_Pid);
num ++;

temp = temp + 4;
}
}

}

void pronum_pmtid_printf()
{
unsigned int i;
printf("PAT table's program_num and PMT's PID:\n");
for(i=0;i<num;i++)
{
printf("program_num = 0x%x (%d),PMT_Pid = 0x%x (%d)\n",
programs[i].program_num,programs[i].program_num,
programs[i].pmt_pid,programs[i].pmt_pid);
}
}

void printf_program_list()
{
unsigned int i;
printf("All PMT Table's program list: \n");

for(i=0;i<program_list_num;i++)
{
printf("stream_type = 0x%x, elementary_pid = 0x%x\n",program_list[i].stream_type,program_list[i].elementary_pid);

}
printf("\n");
}

unsigned char* Find_PMT(unsigned short pmt_pid)
{
unsigned int i=0,j=0;
int pid;
unsigned char *buffer;
buffer = (unsigned char *)malloc(sizeof(char)*188);
memset(buffer,0,sizeof(char)*188);

rewind(file_handle);
for(j=0;j<FileSize/188;j++)
{
Read_Ts_Packet(file_handle,buffer,188);
if(buffer[0] != 0x47)
{
printf("It's not TS packet !\n");

}
else
{
pid = (buffer[1] & 0x1f)<< 8 | buffer[2];
if(pid == pmt_pid)
{
printf("PMT Table already find!\n");
return buffer;
}
else
printf("finding PMT table.......\n");

}

}
}

unsigned char* Find_video_audio(unsigned short program_pid,unsigned char type)
{
unsigned int i = 0, j = 0 ;
int pid;
unsigned char *buffer;

buffer = (unsigned char *)malloc(sizeof(char)*188);
memset(buffer,0,sizeof(char)*188);
rewind(file_handle);
for(j=0;j<FileSize/188;j++)
{
Read_Ts_Packet(file_handle,buffer,188);
if(buffer[0] != 0x47)
{
printf("It's not TS packet !\n");
}
else
{
pid = (buffer[1] & 0x1f)<< 8 | buffer[2];
if(program_pid == pid)
{
if(type == 0x02)
printf("Find a program and this program is Video type!\n");
else if(type == 0x03)
printf("Find a program and this program is Audio type!\n");
else
printf("Find a program but this program is other type !\n");

return buffer;
}
else
printf("finding Video or Audio table.....\n ");

}

}

}
void parse_PMT(unsigned char *buffer,int len,unsigned short pmt_pid)
{

unsigned char *temp, *p;
char adaptation_control;
int adaptation_length,i=0;
int program_info_length;
int ES_info_length;
unsigned short section_length,pid;
temp = buffer;

adaptation_control = temp[3] & 0x30;
if(adaptation_control == 0x10)
{
temp = buffer + 4 +1;
}
else if (adaptation_control == 0x30)
{
adaptation_length = buffer[4];
temp = buffer + 5 + adaptation_length + 1;
}
else
return;

section_length = (temp[1]&0x0f)<<8 | temp[2];
p = temp + 1 + section_length;

// temp = temp + 10;

program_info_length = (temp[10] & 0x0f) << 8 | temp[11];

temp = temp + 12 + program_info_length ;

for(;temp < p - 4;)
{
program_list[program_list_num].stream_type = temp[0],
program_list[program_list_num].elementary_pid = (temp[1]&0x1f) << 8 | temp[2];
ES_info_length = (temp[3]&0x0f) << 8 | temp[4];

temp = temp + 4 + ES_info_length + 1;

program_list_num ++ ;

}

}

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