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     fseek(f[shift<0], shift < 0 ? -shift : shift, SEEK_SET);
 124
 125     fseek(f[0],skip_bytes,SEEK_CUR);
 126     fseek(f[1],skip_bytes,SEEK_CUR);
 127
 128     for(i=0;;){
 129         if( fread(buf[0], SIZE, 1, f[0]) != 1) break;
 130         if( fread(buf[1], SIZE, 1, f[1]) != 1) break;
 131
 132         for(j=0; j<SIZE; i++,j++){
 133             int64_t a= buf[0][j];
 134             int64_t b= buf[1][j];
 135             if(len==2){
 136                 a= (int16_t)(a | (buf[0][++j]<<8));
 137                 b= (int16_t)(b | (buf[1][  j]<<8));
 138             }
 139             sse += (a-b) * (a-b);
 140         }
 141     }
 142
 143     if(!i) i=1;
 144     dev= int_sqrt( ((sse/i)*F*F) + (((sse%i)*F*F) + i/2)/i );
 145     if(sse)
 146         psnr= ((2*log16(max<<16) + log16(i) - log16(sse))*284619LL*F + (1<<31)) / (1LL<<32);
 147     else
 148         psnr= 100*F-1; //floating point free infinity :)
 149
 150     printf("stddev:%3d.%02d PSNR:%2d.%02d bytes:%d\n",
 151         (int)(dev/F), (int)(dev%F),
 152         (int)(psnr/F), (int)(psnr%F),
 153         i*len);
 154     return 0;
 155 }
 156
 157