2 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of FFmpeg.
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.
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.
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
27 #define FFMIN(a, b) ((a) > (b) ? (b) : (a))
31 uint64_t exp16_table[21] = {
56 // 16.16 fixpoint exp()
57 static unsigned int exp16(unsigned int a){
63 out= (out*exp16_table[i] + (1<<15))>>16;
70 // 16.16 fixpoint log()
71 static int64_t log16(uint64_t a)
77 return -log16((1LL << 32) / a);
80 for (i = 20; i >= 0; i--) {
81 int64_t b = exp16_table[i];
85 a = ((a / b) << 16) + (((a % b) << 16) + b / 2) / b;
90 static uint64_t int_sqrt(uint64_t a)
96 for (s = 31; s >= 0; s--) {
97 uint64_t b = ret_sq + (1ULL << (s * 2)) + (ret << s) * 2;
106 static int run_psnr(FILE *f[2], int len, int shift, int skip_bytes)
111 uint8_t buf[2][SIZE];
113 int64_t max = (1 << (8 * len)) - 1;
121 for (i = 0; i < 2; i++) {
123 if (fread(p, 1, 12, f[i]) != 12)
125 if (!memcmp(p, "RIFF", 4) &&
126 !memcmp(p + 8, "WAVE", 4)) {
127 if (fread(p, 1, 8, f[i]) != 8)
129 while (memcmp(p, "data", 4)) {
130 int s = p[4] | p[5] << 8 | p[6] << 16 | p[7] << 24;
131 fseek(f[i], s, SEEK_CUR);
132 if (fread(p, 1, 8, f[i]) != 8)
136 fseek(f[i], -12, SEEK_CUR);
140 fseek(f[shift < 0], abs(shift), SEEK_CUR);
142 fseek(f[0], skip_bytes, SEEK_CUR);
143 fseek(f[1], skip_bytes, SEEK_CUR);
146 int s0 = fread(buf[0], 1, SIZE, f[0]);
147 int s1 = fread(buf[1], 1, SIZE, f[1]);
149 for (j = 0; j < FFMIN(s0, s1); j++) {
150 int64_t a = buf[0][j];
151 int64_t b = buf[1][j];
154 a = (int16_t)(a | (buf[0][++j] << 8));
155 b = (int16_t)(b | (buf[1][ j] << 8));
157 sse += (a - b) * (a - b);
168 i = FFMIN(size0, size1) / len;
171 dev = int_sqrt(((sse / i) * F * F) + (((sse % i) * F * F) + i / 2) / i);
173 psnr = ((2 * log16(max << 16) + log16(i) - log16(sse)) *
174 284619LL * F + (1LL << 31)) / (1LL << 32);
176 psnr = 1000 * F - 1; // floating point free infinity :)
178 printf("stddev:%5d.%02d PSNR:%3d.%02d MAXDIFF:%5d bytes:%9d/%9d\n",
179 (int)(dev / F), (int)(dev % F),
180 (int)(psnr / F), (int)(psnr % F),
181 maxdist, size0, size1);
185 int main(int argc, char *argv[])
188 int len = argc < 4 ? 1 : atoi(argv[3]);
189 int shift_first= argc < 5 ? 0 : atoi(argv[4]);
190 int skip_bytes = argc < 6 ? 0 : atoi(argv[5]);
191 int shift_last = shift_first + (argc < 7 ? 0 : atoi(argv[6]));
194 int max_psnr_shift = 0;
197 printf("tiny_psnr <file1> <file2> [<elem size> [<shift> [<skip bytes> [<shift search range>]]]]\n");
198 printf("WAV headers are skipped automatically.\n");
202 f[0] = fopen(argv[1], "rb");
203 f[1] = fopen(argv[2], "rb");
204 if (!f[0] || !f[1]) {
205 fprintf(stderr, "Could not open input files.\n");
209 for (shift = shift_first; shift <= shift_last; shift++) {
210 int psnr = run_psnr(f, len, shift, skip_bytes);
211 if (psnr > max_psnr || (shift < 0 && psnr == max_psnr)) {
213 max_psnr_shift = shift;
216 if (shift_last > shift_first)
217 printf("Best PSNR is %3d.%02d for shift %i\n", (int)(max_psnr / F), (int)(max_psnr % F), max_psnr_shift);