tiny_psnr.c
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1 /*
2  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
3  *
4  * This file is part of Libav.
5  *
6  * Libav 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  * Libav 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 Libav; 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 <string.h>
24 #include <inttypes.h>
25 #include <assert.h>
26 
27 #include "libavutil/intfloat.h"
28 
29 #define FFMIN(a, b) ((a) > (b) ? (b) : (a))
30 #define F 100
31 #define SIZE 2048
32 
33 uint64_t exp16_table[21] = {
34  65537,
35  65538,
36  65540,
37  65544,
38  65552,
39  65568,
40  65600,
41  65664,
42  65793,
43  66050,
44  66568,
45  67616,
46  69763,
47  74262,
48  84150,
49  108051,
50  178145,
51  484249,
52  3578144,
53  195360063,
54  582360139072LL,
55 };
56 
57 // 16.16 fixpoint log()
58 static int64_t log16(uint64_t a)
59 {
60  int i;
61  int out = 0;
62 
63  if (a < 1 << 16)
64  return -log16((1LL << 32) / a);
65  a <<= 16;
66 
67  for (i = 20; i >= 0; i--) {
68  int64_t b = exp16_table[i];
69  if (a < (b << 16))
70  continue;
71  out |= 1 << i;
72  a = ((a / b) << 16) + (((a % b) << 16) + b / 2) / b;
73  }
74  return out;
75 }
76 
77 static uint64_t int_sqrt(uint64_t a)
78 {
79  uint64_t ret = 0;
80  uint64_t ret_sq = 0;
81  int s;
82 
83  for (s = 31; s >= 0; s--) {
84  uint64_t b = ret_sq + (1ULL << (s * 2)) + (ret << s) * 2;
85  if (b <= a) {
86  ret_sq = b;
87  ret += 1ULL << s;
88  }
89  }
90  return ret;
91 }
92 
93 static int16_t get_s16l(uint8_t *p)
94 {
95  union {
96  uint16_t u;
97  int16_t s;
98  } v;
99  v.u = p[0] | p[1] << 8;
100  return v.s;
101 }
102 
103 static float get_f32l(uint8_t *p)
104 {
105  union av_intfloat32 v;
106  v.i = p[0] | p[1] << 8 | p[2] << 16 | p[3] << 24;
107  return v.f;
108 }
109 
110 int main(int argc, char *argv[])
111 {
112  int i, j;
113  uint64_t sse = 0;
114  uint64_t dev;
115  FILE *f[2];
116  uint8_t buf[2][SIZE];
117  uint64_t psnr;
118  int len = 1;
119  int64_t max;
120  int shift = argc < 5 ? 0 : atoi(argv[4]);
121  int skip_bytes = argc < 6 ? 0 : atoi(argv[5]);
122  int size0 = 0;
123  int size1 = 0;
124  int maxdist = 0;
125 
126  if (argc < 3) {
127  printf("tiny_psnr <file1> <file2> [<elem size> [<shift> [<skip bytes>]]]\n");
128  printf("WAV headers are skipped automatically.\n");
129  return 1;
130  }
131 
132  if (argc > 3) {
133  if (!strcmp(argv[3], "u8")) {
134  len = 1;
135  } else if (!strcmp(argv[3], "s16")) {
136  len = 2;
137  } else if (!strcmp(argv[3], "f32")) {
138  len = 4;
139  } else {
140  char *end;
141  len = strtol(argv[3], &end, 0);
142  if (*end || len < 1 || len > 2) {
143  fprintf(stderr, "Unsupported sample format: %s\n", argv[3]);
144  return 1;
145  }
146  }
147  }
148 
149  max = (1LL << (8 * len)) - 1;
150 
151  f[0] = fopen(argv[1], "rb");
152  f[1] = fopen(argv[2], "rb");
153  if (!f[0] || !f[1]) {
154  fprintf(stderr, "Could not open input files.\n");
155  return 1;
156  }
157 
158  for (i = 0; i < 2; i++) {
159  uint8_t *p = buf[i];
160  if (fread(p, 1, 12, f[i]) != 12)
161  return 1;
162  if (!memcmp(p, "RIFF", 4) &&
163  !memcmp(p + 8, "WAVE", 4)) {
164  if (fread(p, 1, 8, f[i]) != 8)
165  return 1;
166  while (memcmp(p, "data", 4)) {
167  int s = p[4] | p[5] << 8 | p[6] << 16 | p[7] << 24;
168  fseek(f[i], s, SEEK_CUR);
169  if (fread(p, 1, 8, f[i]) != 8)
170  return 1;
171  }
172  } else {
173  fseek(f[i], -12, SEEK_CUR);
174  }
175  }
176 
177  fseek(f[shift < 0], abs(shift), SEEK_CUR);
178 
179  fseek(f[0], skip_bytes, SEEK_CUR);
180  fseek(f[1], skip_bytes, SEEK_CUR);
181 
182  for (;;) {
183  int s0 = fread(buf[0], 1, SIZE, f[0]);
184  int s1 = fread(buf[1], 1, SIZE, f[1]);
185 
186  for (j = 0; j < FFMIN(s0, s1); j += len) {
187  int64_t a = buf[0][j];
188  int64_t b = buf[1][j];
189  int dist;
190  if (len == 2) {
191  a = get_s16l(buf[0] + j);
192  b = get_s16l(buf[1] + j);
193  } else if (len == 4) {
194  a = get_f32l(buf[0] + j) * (1 << 24);
195  b = get_f32l(buf[1] + j) * (1 << 24);
196  } else {
197  a = buf[0][j];
198  b = buf[1][j];
199  }
200  sse += (a - b) * (a - b);
201  dist = abs(a - b);
202  if (dist > maxdist)
203  maxdist = dist;
204  }
205  size0 += s0;
206  size1 += s1;
207  if (s0 + s1 <= 0)
208  break;
209  }
210 
211  i = FFMIN(size0, size1) / len;
212  if (!i)
213  i = 1;
214  dev = int_sqrt(((sse / i) * F * F) + (((sse % i) * F * F) + i / 2) / i);
215  if (sse)
216  psnr = ((2 * log16(max << 16) + log16(i) - log16(sse)) *
217  284619LL * F + (1LL << 31)) / (1LL << 32);
218  else
219  psnr = 1000 * F - 1; // floating point free infinity :)
220 
221  printf("stddev:%5d.%02d PSNR:%3d.%02d MAXDIFF:%5d bytes:%9d/%9d\n",
222  (int)(dev / F), (int)(dev % F),
223  (int)(psnr / F), (int)(psnr % F),
224  maxdist, size0, size1);
225  return 0;
226 }