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/*
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include <assert.h>
#define FFMIN(a, b) ((a) > (b) ? (b) : (a))
#define F 100
#define SIZE 2048
uint64_t exp16_table[21] = {
65537,
65538,
65540,
65544,
65552,
65568,
65600,
65664,
65793,
66050,
66568,
67616,
69763,
74262,
84150,
108051,
178145,
484249,
3578144,
195360063,
582360139072LL,
};
#if 0
// 16.16 fixpoint exp()
static unsigned int exp16(unsigned int a){
int i;
int out= 1<<16;
for(i=19;i>=0;i--){
if(a&(1<<i))
out= (out*exp16_table[i] + (1<<15))>>16;
}
return out;
}
#endif
// 16.16 fixpoint log()
static int64_t log16(uint64_t a)
{
int i;
int out = 0;
if (a < 1 << 16)
return -log16((1LL << 32) / a);
a <<= 16;
for (i = 20; i >= 0; i--) {
int64_t b = exp16_table[i];
if (a < (b << 16))
continue;
out |= 1 << i;
a = ((a / b) << 16) + (((a % b) << 16) + b / 2) / b;
}
return out;
}
static uint64_t int_sqrt(uint64_t a)
{
uint64_t ret = 0;
uint64_t ret_sq = 0;
int s;
for (s = 31; s >= 0; s--) {
uint64_t b = ret_sq + (1ULL << (s * 2)) + (ret << s) * 2;
if (b <= a) {
ret_sq = b;
ret += 1ULL << s;
}
}
return ret;
}
static int run_psnr(FILE *f[2], int len, int shift, int skip_bytes)
{
int i, j;
uint64_t sse = 0;
uint64_t dev;
uint8_t buf[2][SIZE];
uint64_t psnr;
int64_t max = (1 << (8 * len)) - 1;
int size0 = 0;
int size1 = 0;
int maxdist = 0;
int noseek;
noseek = fseek(f[0], 0, SEEK_SET) ||
fseek(f[1], 0, SEEK_SET);
if (!noseek) {
for (i = 0; i < 2; i++) {
uint8_t *p = buf[i];
if (fread(p, 1, 12, f[i]) != 12)
return 1;
if (!memcmp(p, "RIFF", 4) &&
!memcmp(p + 8, "WAVE", 4)) {
if (fread(p, 1, 8, f[i]) != 8)
return 1;
while (memcmp(p, "data", 4)) {
int s = p[4] | p[5] << 8 | p[6] << 16 | p[7] << 24;
fseek(f[i], s, SEEK_CUR);
if (fread(p, 1, 8, f[i]) != 8)
return 1;
}
} else {
fseek(f[i], -12, SEEK_CUR);
}
}
fseek(f[shift < 0], abs(shift), SEEK_CUR);
fseek(f[0], skip_bytes, SEEK_CUR);
fseek(f[1], skip_bytes, SEEK_CUR);
}
for (;;) {
int s0 = fread(buf[0], 1, SIZE, f[0]);
int s1 = fread(buf[1], 1, SIZE, f[1]);
for (j = 0; j < FFMIN(s0, s1); j++) {
int64_t a = buf[0][j];
int64_t b = buf[1][j];
int dist;
if (len == 2) {
a = (int16_t)(a | (buf[0][++j] << 8));
b = (int16_t)(b | (buf[1][ j] << 8));
}
sse += (a - b) * (a - b);
dist = abs(a - b);
if (dist > maxdist)
maxdist = dist;
}
size0 += s0;
size1 += s1;
if (s0 + s1 <= 0)
break;
}
i = FFMIN(size0, size1) / len;
if (!i)
i = 1;
dev = int_sqrt(((sse / i) * F * F) + (((sse % i) * F * F) + i / 2) / i);
if (sse)
psnr = ((2 * log16(max << 16) + log16(i) - log16(sse)) *
284619LL * F + (1LL << 31)) / (1LL << 32);
else
psnr = 1000 * F - 1; // floating point free infinity :)
printf("stddev:%5d.%02d PSNR:%3d.%02d MAXDIFF:%5d bytes:%9d/%9d\n",
(int)(dev / F), (int)(dev % F),
(int)(psnr / F), (int)(psnr % F),
maxdist, size0, size1);
return psnr;
}
int main(int argc, char *argv[])
{
FILE *f[2];
int len = argc < 4 ? 1 : atoi(argv[3]);
int shift_first= argc < 5 ? 0 : atoi(argv[4]);
int skip_bytes = argc < 6 ? 0 : atoi(argv[5]);
int shift_last = shift_first + (argc < 7 ? 0 : atoi(argv[6]));
int shift;
int max_psnr = -1;
int max_psnr_shift = 0;
if (argc < 3) {
printf("tiny_psnr <file1> <file2> [<elem size> [<shift> [<skip bytes> [<shift search range>]]]]\n");
printf("WAV headers are skipped automatically.\n");
return 1;
}
f[0] = fopen(argv[1], "rb");
f[1] = fopen(argv[2], "rb");
if (!f[0] || !f[1]) {
fprintf(stderr, "Could not open input files.\n");
return 1;
}
for (shift = shift_first; shift <= shift_last; shift++) {
int psnr = run_psnr(f, len, shift, skip_bytes);
if (psnr > max_psnr || (shift < 0 && psnr == max_psnr)) {
max_psnr = psnr;
max_psnr_shift = shift;
}
}
if (shift_last > shift_first)
printf("Best PSNR is %3d.%02d for shift %i\n", (int)(max_psnr / F), (int)(max_psnr % F), max_psnr_shift);
return 0;
}
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