helper.c

DVB MPEG2 system stream 分析, 包含 各個talbe(EIT,PMT,PAT,SDT),以及video,audio. 對於學習數字電視有很大幫助.

 startbit = 56 - startbit - bitlen;
 tmp      = tmp >> startbit;
 mask     = (1ULL << bitlen) - 1;	// 1ULL !!!
 v        = tmp & mask;

 return v;
}



/*
  -- get bits out of buffer   (max 64 bit)
  -- extended bitrange, so it's slower 
  -- return: value
 */

unsigned long long getBits64 (u_char *buf, int byte_offset, int startbit, int bitlen)
{
  unsigned long long x1,x2,x3;

  if (bitlen <= 32) {
     x3 = getBits (buf,byte_offset,startbit,bitlen); 
  } else {
     x1 = getBits (buf,byte_offset,startbit,32); 
     x2 = getBits (buf,byte_offset,startbit+32,bitlen-32); 
     x3 = (x1<<(bitlen-32)) + x2;
  }
  return x3;
}






/*
  -----------------------------------------------------------------------------------
 */




/*
  -- get ISO 639  (3char) language code into string[4]
  -- terminate string with \0
  -- return ptr to buf;
 */

u_char *getISO639_3 (u_char *str, u_char *buf)
{
  int i;

  strncpy (str, buf, 3);
  *(str+3) = '\0';

  // secure print of string
  for (i=0; i<3; i++) 
  {
     if (!isprint(*(str+i))) 
	 {
	     *(str+i) = '.';
     }
  }
  
  return str;
}




/*
  -- print_text_468A 
  -- ETSI EN 300 468  Annex A
  -- evaluate string and look on DVB control codes
  -- print the string
*/

static void print_text2_468A (int v, u_char *b, u_int len);

void print_text_468A (int v, const char *s,  u_char *b, u_int len)
{

 out (v, s);

 if (len <= 0) {
    out_nl (v,"\"\"");
 } else {
    out (v,"\"");
    print_text2_468A (v, b,len);
    out (v,"\"");
    out_nl (v,"  -- Charset: %s", dvbstrTextCharset_TYPE (*b));
 }

}


static void print_text2_468A (int v, u_char *b, u_int len)
{
  int    in_emphasis = 0;
  int    i;
  u_char c;
  u_char em_ON  = 0x86;
  u_char em_OFF = 0x87;

 
  for (i=0; i<len; i++) 
  {
    c = b[i];

    if (i == 0 && c < 0x20) continue;   // opt. charset descript.

    if (c == em_ON) {
       in_emphasis = 1;
       out (v,"<EM>");
       continue;
    }
    if (c == em_OFF) {
       in_emphasis = 0;
       out (v,"</EM>");
       continue;
    }

       if (c == 0x8A)     out (v, "<BR>");
       else if (c < 0x20) out (v, ".");
       else               out (v, "%c", c);

  } // for
  

}


/*
  -- print_text_UTF8
  -- print the string using UTF8
  -- (use std_ascii)
*/

void print_text_UTF8 (int v, const char *s,  u_char *b, u_int len)
{
   print_std_ascii (v, s, b, len);
}



/*
  -- print standard ascii text
*/

void print_std_ascii (int v, const char *s, u_char *b, u_int len)
{
  int    i;
  u_char c;
 
  out (v,"%s\"",s);
  for (i=0; i<len; i++) {
    c = b[i];
    if (!isprint (c)) c = '.';
    out (v, "%c", c);
  } 
  out_nl (v,"\"");

}






/*
 -- print time   40 bit
 --   16 Bit  MJD,  24 Bit UTC
*/ 

void print_time40 (int v, u_long mjd, u_long utc)
{
 out (v, "0x%lx%06lx (=",mjd, utc);

 if (mjd > 0) 
 {
   long   y,m,d ,k;
   // algo: ETSI EN 300 468 - ANNEX C

   y =  (long) ((mjd  - 15078.2) / 365.25);
   m =  (long) ((mjd - 14956.1 - (long)(y * 365.25) ) / 30.6001);
   d =  (long) (mjd - 14956 - (long)(y * 365.25) - (long)(m * 30.6001));
   k =  (m == 14 || m == 15) ? 1 : 0;
   y = y + k + 1900;
   m = m - 1 - k*12;

   out (v, "%02d-%02d-%02d",y,m,d);
 }

 out (v, " %02lx:%02lx:%02lx [UTC])",
	 (utc>>16) &0xFF, (utc>>8) &0xFF, (utc) &0xFF);

}






/*
  -- print data bytes (str + hexdump)
  -- print  "Private Data" and Hex-Dump

*/
void print_databytes (int v, const char *str, u_char *b, u_int len)
{
  if (len > 0) {
     out_nl (v,str);
	indent (+1);
	printhex_buf (v+1,b,len);
	indent (-1);
  }
}

void print_private_data (int v, u_char *b, u_int len)
{
  print_databytes (v,"Private Data:",b,len);
}

void print_databytes_line  (int v, const char *str, u_char *b, u_int len)
{
  if (len > 0) {
     out (v,"%s ",str);
     printhexline_buf (v+1,b,len);
  }
}









/*
   -- str2i
   -- string to integer
   --   x, 0x ist Hex
   --   ansonsten Dezimal
   return:  long int

*/

long  str2i  (char *s)
{
 long v;
 
 if (!s) {
	 fprintf (stderr,"str2i: NULL ptr (abort)\n");
	 exit(-1);
 }

 v = strtol (s, NULL, 0);
 return v;

}








/*
 -- latitude coordinates   (Cell Descriptors)
 -- longitude coordinates   (Cell Descriptors)
 -- ETSI EN 300 468
*/ 

static char *_str_cell_latitude_longitude (long ll, int angle);

char *str_cell_latitude (long latitude)
{
 // cell_latitude: This 16-bit field, coded as a two's complement number,
 // shall specify the latitude of the corner of a spherical rectangle that
 // approximately describes the coverage area of the cell indicated. It shall
 // be calculated by multiplying the value of the latitude field by
 // (90 ?/2^15 ). Southern latitudes shall be considered negative and
 // northern latitudes positive.

 return _str_cell_latitude_longitude (latitude, 90);
}


char *str_cell_longitude (long longitude)
{
 // cell_longitude: This 16-bit field, coded as a two's complement number, shall
 // specify the longitude of the corner of a spherical rectangle that approximately
 // describes the coverage area of the cell indicated. It shall be calculated by
 // multiplying the value of the longitude field by (180 ?/2^15 ). Western
 // longitudes shall be considered negative and eastern longitudes positive.

 return _str_cell_latitude_longitude (longitude, 180);
}


static char *_str_cell_latitude_longitude (long ll, int angle)
{
 long long  x;
 long       g1,g2;
 static     char s[40];	// $$$ not thread safe!

 x = (long long) ll * angle * 1000;
 x = x / (2<<15);

 g1 = x / 1000;
 g2 = x % 1000;
 if (g2 <0) g2 = 0 - g2;

 sprintf (s,"%ld.%04ld grad",g1,g2);
 return s;
}





/*
 * -- display MAC-Address format
 *  -- input:  High- and Low Word (each 24bit)
 */

void displ_mac_addr (int v, long mac_H24, long mac_L24)
{

   out (v,"%02x:%02x:%02x",
	   (mac_H24>>16) & 0xFF, (mac_H24>>8) & 0xFF, mac_H24 & 0xFF);
   out (v,"%02x:%02x:%02x",
	   (mac_L24>>16) & 0xFF, (mac_L24>>8) & 0xFF, mac_L24 & 0xFF);

}




/*
 * -- display IP-Address format
 *  -- input: IP-Addr. 
 */

void displ_IPv4_addr (int v, u_long ip)
{
   out (v,"%d.%d.%d.%d",
	(ip>>24) & 0xFF, (ip>>16) & 0xFF, (ip>>8) & 0xFF, ip & 0xFF);
}



/*
 * -- display IPv6-Address format
 *  -- input: IPv6-Addr. 
 */

void displ_IPv6_addr (int v, struct IPv6ADDR *a)
{
   out (v,"%x:%x:%x:%x:%x:%x:%x:%x",
	(a->ip[0]>>16) & 0xFFFF, (a->ip[0]) & 0xFFFF,
	(a->ip[1]>>16) & 0xFFFF, (a->ip[1]) & 0xFFFF,
	(a->ip[2]>>16) & 0xFFFF, (a->ip[2]) & 0xFFFF,
	(a->ip[3]>>16) & 0xFFFF, (a->ip[3]) & 0xFFFF
       );
}








/*
 * --  return a bit string for value, len bits
 * --  NOT thread-safe !!!  $$$
 */

char *str_bit32 (u_long value, int bits)
{
   static char bitstr[65];
   char *s = bitstr;

   if (bits > 64) bits = 64;
   s += bits;

   // reverse bit shift to get real order
 
   *s = '\0';
   while (bits-- > 0) {
	   *(--s) = (value & 0x01) ? '1' :'0';
	   value = value >> 1;
   }

   return bitstr;
}