int main(void)
{
     FILE *source, *dest;
     char octet;
     source = fopen("blablabla","r");
     dest = fopen("blablabla2","w");

while (fread(octet, 1, 1, source))
{
    fwrite(octet+octet*16, 1, 1, dest);
}

}

enjouaille.