Fix segfault with non existing input files.
[libav.git] / tests / tiny_psnr.c
1 /*
2 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <inttypes.h>
24 #include <assert.h>
25
26 #define F 100
27 #define SIZE 2048
28
29 uint64_t exp16_table[21]={
30 65537,
31 65538,
32 65540,
33 65544,
34 65552,
35 65568,
36 65600,
37 65664,
38 65793,
39 66050,
40 66568,
41 67616,
42 69763,
43 74262,
44 84150,
45 108051,
46 178145,
47 484249,
48 3578144,
49 195360063,
50 582360139072LL,
51 };
52
53 #if 0
54 // 16.16 fixpoint exp()
55 static unsigned int exp16(unsigned int a){
56 int i;
57 int out= 1<<16;
58
59 for(i=19;i>=0;i--){
60 if(a&(1<<i))
61 out= (out*exp16_table[i] + (1<<15))>>16;
62 }
63
64 return out;
65 }
66 #endif
67
68 // 16.16 fixpoint log()
69 static int64_t log16(uint64_t a){
70 int i;
71 int out=0;
72
73 if(a < 1<<16)
74 return -log16((1LL<<32) / a);
75 a<<=16;
76
77 for(i=20;i>=0;i--){
78 int64_t b= exp16_table[i];
79 if(a<(b<<16)) continue;
80 out |= 1<<i;
81 a = ((a/b)<<16) + (((a%b)<<16) + b/2)/b;
82 }
83 return out;
84 }
85
86 static uint64_t int_sqrt(uint64_t a)
87 {
88 uint64_t ret=0;
89 int s;
90 uint64_t ret_sq=0;
91
92 for(s=31; s>=0; s--){
93 uint64_t b= ret_sq + (1ULL<<(s*2)) + (ret<<s)*2;
94 if(b<=a){
95 ret_sq=b;
96 ret+= 1ULL<<s;
97 }
98 }
99 return ret;
100 }
101
102 int main(int argc,char* argv[]){
103 int i, j;
104 uint64_t sse=0;
105 uint64_t dev;
106 FILE *f[2];
107 uint8_t buf[2][SIZE];
108 uint64_t psnr;
109 int len= argc<4 ? 1 : atoi(argv[3]);
110 int64_t max= (1<<(8*len))-1;
111 int shift= argc<5 ? 0 : atoi(argv[4]);
112 int skip_bytes = argc<6 ? 0 : atoi(argv[5]);
113
114 if(argc<3){
115 printf("tiny_psnr <file1> <file2> [<elem size> [<shift> [<skip bytes>]]]\n");
116 printf("for wav files use the following:\n");
117 printf("./tiny_psnr file1.wav file2.wav 2 0 44 to skip the header.\n");
118 return -1;
119 }
120
121 f[0]= fopen(argv[1], "rb");
122 f[1]= fopen(argv[2], "rb");
123 if(!f[0] || !f[1]){
124 fprintf(stderr, "couldnt open input files\n");
125 return -1;
126 }
127 fseek(f[shift<0], shift < 0 ? -shift : shift, SEEK_SET);
128
129 fseek(f[0],skip_bytes,SEEK_CUR);
130 fseek(f[1],skip_bytes,SEEK_CUR);
131
132 for(i=0;;){
133 if( fread(buf[0], SIZE, 1, f[0]) != 1) break;
134 if( fread(buf[1], SIZE, 1, f[1]) != 1) break;
135
136 for(j=0; j<SIZE; i++,j++){
137 int64_t a= buf[0][j];
138 int64_t b= buf[1][j];
139 if(len==2){
140 a= (int16_t)(a | (buf[0][++j]<<8));
141 b= (int16_t)(b | (buf[1][ j]<<8));
142 }
143 sse += (a-b) * (a-b);
144 }
145 }
146
147 if(!i) i=1;
148 dev= int_sqrt( ((sse/i)*F*F) + (((sse%i)*F*F) + i/2)/i );
149 if(sse)
150 psnr= ((2*log16(max<<16) + log16(i) - log16(sse))*284619LL*F + (1<<31)) / (1LL<<32);
151 else
152 psnr= 100*F-1; //floating point free infinity :)
153
154 printf("stddev:%3d.%02d PSNR:%2d.%02d bytes:%d\n",
155 (int)(dev/F), (int)(dev%F),
156 (int)(psnr/F), (int)(psnr%F),
157 i*len);
158 return 0;
159 }
160
161