tests/tiny_psnr.c

   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 #define FFMIN(a, b) ((a) > (b) ? (b) : (a))
  28 #define F 100
  29 #define SIZE 2048
  30
  31 uint64_t exp16_table[21] = {
  32            65537,
  33            65538,
  34            65540,
  35            65544,
  36            65552,
  37            65568,
  38            65600,
  39            65664,
  40            65793,
  41            66050,
  42            66568,
  43            67616,
  44            69763,
  45            74262,
  46            84150,
  47           108051,
  48           178145,
  49           484249,
  50          3578144,
  51        195360063,
  52     582360139072LL,
  53 };
  54
  55 // 16.16 fixpoint log()
  56 static int64_t log16(uint64_t a)
  57 {
  58     int i;
  59     int out = 0;
  60
  61     if (a < 1 << 16)
  62         return -log16((1LL << 32) / a);
  63     a <<= 16;
  64
  65     for (i = 20; i >= 0; i--) {
  66         int64_t b = exp16_table[i];
  67         if (a < (b << 16))
  68             continue;
  69         out |= 1 << i;
  70         a    = ((a / b) << 16) + (((a % b) << 16) + b / 2) / b;
  71     }
  72     return out;
  73 }
  74
  75 static uint64_t int_sqrt(uint64_t a)
  76 {
  77     uint64_t ret    = 0;
  78     uint64_t ret_sq = 0;
  79     int s;
  80
  81     for (s = 31; s >= 0; s--) {
  82         uint64_t b = ret_sq + (1ULL << (s * 2)) + (ret << s) * 2;
  83         if (b <= a) {
  84             ret_sq = b;
  85             ret   += 1ULL << s;
  86         }
  87     }
  88     return ret;
  89 }
  90
  91 int main(int argc, char *argv[])
  92 {
  93     int i, j;
  94     uint64_t sse = 0;
  95     uint64_t dev;
  96     FILE *f[2];
  97     uint8_t buf[2][SIZE];
  98     uint64_t psnr;
  99     int len        = argc < 4 ? 1 : atoi(argv[3]);
 100     int64_t max    = (1 << (8 * len)) - 1;
 101     int shift      = argc < 5 ? 0 : atoi(argv[4]);
 102     int skip_bytes = argc < 6 ? 0 : atoi(argv[5]);
 103     int size0      = 0;
 104     int size1      = 0;
 105     int maxdist    = 0;
 106
 107     if (argc < 3) {
 108         printf("tiny_psnr <file1> <file2> [<elem size> [<shift> [<skip bytes>]]]\n");
 109         printf("WAV headers are skipped automatically.\n");
 110         return 1;
 111     }
 112
 113     f[0] = fopen(argv[1], "rb");
 114     f[1] = fopen(argv[2], "rb");
 115     if (!f[0] || !f[1]) {
 116         fprintf(stderr, "Could not open input files.\n");
 117         return 1;
 118     }
 119
 120     for (i = 0; i < 2; i++) {
 121         uint8_t *p = buf[i];
 122         if (fread(p, 1, 12, f[i]) != 12)
 123             return 1;
 124         if (!memcmp(p, "RIFF", 4) &&
 125             !memcmp(p + 8, "WAVE", 4)) {
 126             if (fread(p, 1, 8, f[i]) != 8)
 127                 return 1;
 128             while (memcmp(p, "data", 4)) {
 129                 int s = p[4] | p[5] << 8 | p[6] << 16 | p[7] << 24;
 130                 fseek(f[i], s, SEEK_CUR);
 131                 if (fread(p, 1, 8, f[i]) != 8)
 132                     return 1;
 133             }
 134         } else {
 135             fseek(f[i], -12, SEEK_CUR);
 136         }
 137     }
 138
 139     fseek(f[shift < 0], abs(shift), SEEK_CUR);
 140
 141     fseek(f[0], skip_bytes, SEEK_CUR);
 142     fseek(f[1], skip_bytes, SEEK_CUR);
 143
 144     for (;;) {
 145         int s0 = fread(buf[0], 1, SIZE, f[0]);
 146         int s1 = fread(buf[1], 1, SIZE, f[1]);
 147
 148         for (j = 0; j < FFMIN(s0, s1); j++) {
 149             int64_t a = buf[0][j];
 150             int64_t b = buf[1][j];
 151             int dist;
 152             if (len == 2) {
 153                 a = (int16_t)(a | (buf[0][++j] << 8));
 154                 b = (int16_t)(b | (buf[1][  j] << 8));
 155             }
 156             sse += (a - b) * (a - b);
 157             dist = abs(a - b);
 158             if (dist > maxdist)
 159                 maxdist = dist;
 160         }
 161         size0 += s0;
 162         size1 += s1;
 163         if (s0 + s1 <= 0)
 164             break;
 165     }
 166
 167     i = FFMIN(size0, size1) / len;
 168     if (!i)
 169         i = 1;
 170     dev = int_sqrt(((sse / i) * F * F) + (((sse % i) * F * F) + i / 2) / i);
 171     if (sse)
 172         psnr = ((2 * log16(max << 16) + log16(i) - log16(sse)) *
 173                 284619LL * F + (1LL << 31)) / (1LL << 32);
 174     else
 175         psnr = 1000 * F - 1; // floating point free infinity :)
 176
 177     printf("stddev:%5d.%02d PSNR:%3d.%02d MAXDIFF:%5d bytes:%9d/%9d\n",
 178            (int)(dev / F), (int)(dev % F),
 179            (int)(psnr / F), (int)(psnr % F),
 180            maxdist, size0, size1);
 181     return 0;
 182 }