Noise Generator in Linux

Linux noise generator-general Linux technology-Linux programming and kernel information. For details, see the following. It may be useful to get the white noise generator program under linux and share it. Next, solve the driver problem.

# Include
# Include
# Include
# Include
# Include
# Include
# Include
# Include
# Define BUFSIZE 88200 // 100 ms wav is generated every time
# Define count 100 // 10 s data is produced


Char magic [] = {0x52,0x49,0x46,0x46}; // "wave"
Char middle [] = {0x57,0x41,0x56,0x45,0x66, 0x6D, 0x74,0x20,
0 x, 0 x, 0 x, 0 x, 0 x, 0 x,
0x44, 0xAC, 0 x, 0 x, 0x10, 0xB1, 0 x, 0x00,
0 x, 0 x, 0 x, 0x64, 0x61}; // other frame data

Short rxbuf [BUFSIZE];

Void write_wavheader (int fd, int data_len)
{
Int tmp;
Write (fd, magic, 4 );
Tmp = data_len + 36;
Write (fd, (char *) & tmp, 4 );
Write (fd, middle, 32 );
Tmp = data_len;
Write (fd, (char *) & tmp, 4 );
}




Int main (int argc, char ** argv)
{

Int out_fd;
Int I, j, realsize;
Int output;
Char * filename;

Filename = "/tmp/out.wav ";
If (out_fd = open (filename, O_RDWR | O_CREAT | O_TRUNC), 0666) <= 0)
{
Printf ("Can't open output file! Errno = % d \ n ", errno );
Return;
}
Memset (rxbuf, 0, BUFSIZE * sizeof (short ));
Write_wavheader (out_fd, count * BUFSIZE );
For (I = 0; I {
For (j = 0; j {
Rxbuf [j] = (short) (32760.0 * rand ()/(RAND_MAX + 1.0 ));
If (rxbuf [j] % 2 = 0)
Rxbuf [j] * =-1;
}

If (realsize = write (out_fd, rxbuf, BUFSIZE * sizeof (short )))! = BUFSIZE * sizeof (short ))
Printf ("ERROR: write (% s) return count: 0x % d, errno: % d \ n", filename, realsize, errno );
}

Printf ("\ nRecord finished. \ n ");
Return 0;
}