1 /*
2  * compare.c
3  * Copyright (C) 2000-2002 Michel Lespinasse <walken@zoy.org>
4  * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
5  *
6  * This file is part of a52dec, a free ATSC A-52 stream decoder.
7  * See http://liba52.sourceforge.net/ for updates.
8  *
9  * a52dec is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * a52dec is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
22  */
23 
24 #include <stdio.h>
25 #include <math.h>
26 
main(int argc,char ** argv)27 int main (int argc, char ** argv)
28 {
29     FILE * f1;
30     FILE * f2;
31     float buf1[512];
32     float buf2[512];
33     int i, j;
34     int total = 0;
35     double max = 0, err = 0, square = 0;
36 
37     if (argc != 3)
38 	return 1;
39     f1 = fopen (argv[1], "rb");
40     f2 = fopen (argv[2], "rb");
41     if ((f1 == NULL) || (f2 == NULL)) {
42 	printf ("cannot open file %s\n", (f1 == NULL) ? argv[1] : argv[2]);
43 	return 1;
44     }
45     while (1) {
46 	i = fread (buf1, sizeof (float), 512, f1);
47 	j = fread (buf2, sizeof (float), 512, f2);
48 	if ((i < 512) || (j < 512))
49 	    break;
50 	for (i = 0; i < 512; i++) {
51 	    double delta;
52 
53 	    delta = buf2[i] - buf1[i];
54 	    err += delta;
55 	    square += delta * delta;
56 	    if (delta > max)
57 		max = delta;
58 	    if (-delta > max)
59 		max = -delta;
60 	}
61 	total += 512;
62     }
63     if (i == j) {
64 	err /= total;
65 	square = (square / total) - (err * err);
66 	if (square > 0)
67 	    square = 32768 * sqrt (square);
68 	err *= 32768;
69 	max *= 32768;
70 	printf ("max error %f mean error %f standard deviation %f\n",
71 		max, err, square);
72 	return ((max > 0.01) || (err > 0.001) || (square > 0.001));
73     }
74     if (i < j)
75 	printf ("%s is too short\n", argv[1]);
76     else
77 	printf ("%s is too short\n", argv[2]);
78     return 1;
79 }
80