tracker/readraw/findstart.c

/************************************************************
*     11/9/2005 modified by david fedele to read buffer-data
*     instead raw-data-file 
**************************************************************
 
* include needed system headers
*/
#include <stdio.h>       /* include standard i/o library */
#include <stdlib.h>      /* include standard library */
#include <string.h>      /* include string library */
#include <unistd.h>      /* include unix standard library */
#include <sys/types.h>   /* */
#include <sys/stat.h>    /* */
#include <fcntl.h>       /* */
#include <errno.h>       /* error simbol definitions */
#include <time.h>        /* system time definitions */
#include <math.h>        /* math library */

/*   looks for a DSP header beginning (a word beginning with 1110)   */

/************************************************************
*     11/9/2005 modified by david fedele
*       void findstart_(int *error, int *fd)*/
void getbytes_(int *nbytes, char *buffer, int *p, unsigned int *value);

void findstart_(int *error,char *buffer, int *len, int *curpos)
{
    char *buff=buffer;
    int nbytes2=2;
    /* int nread */
/*     unsigned short word; */
/*     unsigned short temp; */
    unsigned int word;
/***********************************************************/
    
    *error=0;
    do {
/************************************************************/
/*     11/9/2005 modified by david fedele                   */
/*        nread=read(*fd, &word, 2); //reads 16 bits        */
/*      if(nread == 0) { */
/* //       printf("findstart: Unexpected end of file %d at %d \n",*fd,nread); */
/*          *error=1; */
/*          return ; */
/*      } */
/*      if(nread != 2) { */
/* //       printf("findstart: Error on reading: bytes read -> nread = %d \n",nread); */
/*          *error=-1; */
/*          return ; */
/*      } */

/*      /\*** corrects byte ***\/ //endianess... */
/*      temp = word; */
/*      word = ( (temp&0x00ff) << 8 ) | ( (temp&0xff00) >> 8 ); */
/* //   printf("word %x , temp: %x: \n", word, temp);//???  */

/*         /\*** goes back 8 bits ***\/ */
/*      lseek(*fd, -1, SEEK_CUR); //SEEK_CUR ---> from current position */

/* //   unsigned short num=lseek(*fd, -1, SEEK_CUR); //SEEK_CUR ---> from current position */
/* //   printf("%i \n",num); */
     
        getbytes_(&nbytes2,buff,curpos,&word);
           
      *curpos=*curpos-1;
      if(*curpos-1 > *len) {
          printf("findstart: Unexpected end of file \n"); 
          *error=1;
          return ;
      }
/***********************************************************/
  
    }     while ((word&0xf000) != 0xe000);
    
/************************************************************/
/*     11/9/2005 modified by david fedele                   */
/*     /\*** goes back 8 bits ***\/ */
/*     lseek(*fd, -1, SEEK_CUR); */
    *curpos=*curpos-1;
    
/************************************************************/
    return;
}
1	/************************************************************
2	* 11/9/2005 modified by david fedele to read buffer-data
3	* instead raw-data-file
4	**************************************************************
5
6	* include needed system headers
7	*/
8	#include <stdio.h> /* include standard i/o library */
9	#include <stdlib.h> /* include standard library */
10	#include <string.h> /* include string library */
11	#include <unistd.h> /* include unix standard library */
12	#include <sys/types.h> /* */
13	#include <sys/stat.h> /* */
14	#include <fcntl.h> /* */
15	#include <errno.h> /* error simbol definitions */
16	#include <time.h> /* system time definitions */
17	#include <math.h> /* math library */
18
19	/* looks for a DSP header beginning (a word beginning with 1110) */
20
21	/************************************************************
22	* 11/9/2005 modified by david fedele
23	* void findstart_(int error, int fd)*/
24	void getbytes_(int nbytes, char buffer, int p, unsigned int value);
25
26	void findstart_(int error,char buffer, int len, int curpos)
27	{
28	char *buff=buffer;
29	int nbytes2=2;
30	/* int nread */
31	/* unsigned short word; */
32	/* unsigned short temp; */
33	unsigned int word;
34	/***********************************************************/
35
36	*error=0;
37	do {
38	/************************************************************/
39	/* 11/9/2005 modified by david fedele */
40	/* nread=read(fd, &word, 2); //reads 16 bits /
41	/* if(nread == 0) { */
42	/* // printf("findstart: Unexpected end of file %d at %d \n",fd,nread); /
43	/* error=1; /
44	/* return ; */
45	/* } */
46	/* if(nread != 2) { */
47	/* // printf("findstart: Error on reading: bytes read -> nread = %d \n",nread); */
48	/* error=-1; /
49	/* return ; */
50	/* } */
51
52	/* /\* corrects byte \/ //endianess... /
53	/* temp = word; */
54	/* word = ( (temp&0x00ff) << 8 ) \| ( (temp&0xff00) >> 8 ); */
55	/* // printf("word %x , temp: %x: \n", word, temp);//??? */
56
57	/* /\* goes back 8 bits \/ /
58	/* lseek(fd, -1, SEEK_CUR); //SEEK_CUR ---> from current position /
59
60	/* // unsigned short num=lseek(fd, -1, SEEK_CUR); //SEEK_CUR ---> from current position /
61	/* // printf("%i \n",num); */
62
63	getbytes_(&nbytes2,buff,curpos,&word);
64
65	curpos=curpos-1;
66	if(curpos-1 > len) {
67	printf("findstart: Unexpected end of file \n");
68	*error=1;
69	return ;
70	}
71	/***********************************************************/
72
73	} while ((word&0xf000) != 0xe000);
74
75	/************************************************************/
76	/* 11/9/2005 modified by david fedele */
77	/* /\* goes back 8 bits \/ /
78	/* lseek(fd, -1, SEEK_CUR); /
79	curpos=curpos-1;
80
81	/************************************************************/
82	return;
83	}