数字电视pmt表解析C语言程序

以下是一个简单的C语言程序，用于解析数字电视PMT表：

#include <stdio.h>
#include <stdlib.h>

#define PMT_START_CODE 0x2
#define PMT_PID 0x1000
#define PMT_SECTION_LENGTH 1024

typedef struct {
    unsigned char table_id;
    unsigned short section_syntax_indicator;
    unsigned short section_length;
    unsigned short program_number;
    unsigned short version_number;
    unsigned short current_next_indicator;
    unsigned char section_number;
    unsigned char last_section_number;
    unsigned short PCR_PID;
    unsigned short program_info_length;
} PMT_header;

typedef struct {
    unsigned short stream_type;
    unsigned short elementary_PID;
    unsigned short ES_info_length;
} PMT_stream;

int main() {
    FILE *fp;
    unsigned char buffer[PMT_SECTION_LENGTH];
    int n, i, j, k, l;
    PMT_header header;
    PMT_stream stream;

    fp = fopen("pmt.bin", "rb");
    if (fp == NULL) {
        printf("Failed to open file.\n");
        return 1;
    }

    n = fread(buffer, 1, PMT_SECTION_LENGTH, fp);
    if (n != PMT_SECTION_LENGTH) {
        printf("Failed to read file.\n");
        fclose(fp);
        return 1;
    }

    if (buffer[0] != PMT_START_CODE || ((buffer[1] << 8) | buffer[2]) != PMT_PID) {
        printf("Invalid PMT table.\n");
        fclose(fp);
        return 1;
    }

    header.table_id = buffer[0];
    header.section_syntax_indicator = (buffer[1] >> 7) & 0x1;
    header.section_length = ((buffer[1] & 0x0F) << 8) | buffer[2];
    header.program_number = (buffer[3] << 8) | buffer[4];
    header.version_number = (buffer[5] >> 1) & 0x1F;
    header.current_next_indicator = buffer[5] & 0x1;
    header.section_number = buffer[6];
    header.last_section_number = buffer[7];
    header.PCR_PID = ((buffer[8] & 0x1F) << 8) | buffer[9];
    header.program_info_length = ((buffer[10] & 0x0F) << 8) | buffer[11];

    printf("Table ID: %d\n", header.table_id);
    printf("Section syntax indicator: %d\n", header.section_syntax_indicator);
    printf("Section length: %d\n", header.section_length);
    printf("Program number: %d\n", header.program_number);
    printf("Version number: %d\n", header.version_number);
    printf("Current/Next indicator: %d\n", header.current_next_indicator);
    printf("Section number: %d\n", header.section_number);
    printf("Last section number: %d\n", header.last_section_number);
    printf("PCR PID: %d\n", header.PCR_PID);
    printf("Program info length: %d\n", header.program_info_length);

    i = 12 + header.program_info_length;
    while (i < header.section_length - 4) {
        stream.stream_type = buffer[i];
        stream.elementary_PID = ((buffer[i + 1] & 0x1F) << 8) | buffer[i + 2];
        stream.ES_info_length = ((buffer[i + 3] & 0x0F) << 8) | buffer[i + 4];

        printf("\nStream Type: %d\n", stream.stream_type);
        printf("Elementary PID: %d\n", stream.elementary_PID);
        printf("ES Info Length: %d\n", stream.ES_info_length);

        i += 5 + stream.ES_info_length;
    }

    fclose(fp);
    return 0;
}

这个程序使用了两个结构体，一个用于存储PMT头部信息，另一个用于存储每个流的信息。程序首先打开一个名为“pmt.bin”的文件，读取1024个字节的数据到缓冲区中。接下来，程序检查PMT表的开始码和PID是否正确，如果不正确则退出。然后程序解析头部信息，并打印出来。最后，程序解析每个流的信息，并打印出来。