1/* 2 * Copyright (c) 2003-2013 Loren Merritt 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110 USA 17 */ 18/* 19 * tiny_ssim.c 20 * Computes the Structural Similarity Metric between two rawYV12 video files. 21 * original algorithm: 22 * Z. Wang, A. C. Bovik, H. R. Sheikh and E. P. Simoncelli, 23 * "Image quality assessment: From error visibility to structural similarity," 24 * IEEE Transactions on Image Processing, vol. 13, no. 4, pp. 600-612, Apr. 2004. 25 * 26 * To improve speed, this implementation uses the standard approximation of 27 * overlapped 8x8 block sums, rather than the original gaussian weights. 28 */ 29 30#include <inttypes.h> 31#include <limits.h> 32#include <math.h> 33#include <stdio.h> 34#include <stdlib.h> 35 36#define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0) 37#define FFMIN(a,b) ((a) > (b) ? (b) : (a)) 38 39#define BIT_DEPTH 8 40#define PIXEL_MAX ((1 << BIT_DEPTH)-1) 41typedef uint8_t pixel; 42 43/**************************************************************************** 44 * structural similarity metric 45 ****************************************************************************/ 46static void ssim_4x4x2_core( const pixel *pix1, intptr_t stride1, 47 const pixel *pix2, intptr_t stride2, 48 int sums[2][4] ) 49{ 50 int x,y,z; 51 52 for( z = 0; z < 2; z++ ) 53 { 54 uint32_t s1 = 0, s2 = 0, ss = 0, s12 = 0; 55 for( y = 0; y < 4; y++ ) 56 for( x = 0; x < 4; x++ ) 57 { 58 int a = pix1[x+y*stride1]; 59 int b = pix2[x+y*stride2]; 60 s1 += a; 61 s2 += b; 62 ss += a*a; 63 ss += b*b; 64 s12 += a*b; 65 } 66 sums[z][0] = s1; 67 sums[z][1] = s2; 68 sums[z][2] = ss; 69 sums[z][3] = s12; 70 pix1 += 4; 71 pix2 += 4; 72 } 73} 74 75static float ssim_end1( int s1, int s2, int ss, int s12 ) 76{ 77/* Maximum value for 10-bit is: ss*64 = (2^10-1)^2*16*4*64 = 4286582784, which will overflow in some cases. 78 * s1*s1, s2*s2, and s1*s2 also obtain this value for edge cases: ((2^10-1)*16*4)^2 = 4286582784. 79 * Maximum value for 9-bit is: ss*64 = (2^9-1)^2*16*4*64 = 1069551616, which will not overflow. */ 80#if BIT_DEPTH > 9 81 typedef float type; 82 static const float ssim_c1 = .01*.01*PIXEL_MAX*PIXEL_MAX*64; 83 static const float ssim_c2 = .03*.03*PIXEL_MAX*PIXEL_MAX*64*63; 84#else 85 typedef int type; 86 static const int ssim_c1 = (int)(.01*.01*PIXEL_MAX*PIXEL_MAX*64 + .5); 87 static const int ssim_c2 = (int)(.03*.03*PIXEL_MAX*PIXEL_MAX*64*63 + .5); 88#endif 89 type fs1 = s1; 90 type fs2 = s2; 91 type fss = ss; 92 type fs12 = s12; 93 type vars = fss*64 - fs1*fs1 - fs2*fs2; 94 type covar = fs12*64 - fs1*fs2; 95 return (float)(2*fs1*fs2 + ssim_c1) * (float)(2*covar + ssim_c2) 96 / ((float)(fs1*fs1 + fs2*fs2 + ssim_c1) * (float)(vars + ssim_c2)); 97} 98 99static float ssim_end4( int sum0[5][4], int sum1[5][4], int width ) 100{ 101 float ssim = 0.0; 102 int i; 103 104 for( i = 0; i < width; i++ ) 105 ssim += ssim_end1( sum0[i][0] + sum0[i+1][0] + sum1[i][0] + sum1[i+1][0], 106 sum0[i][1] + sum0[i+1][1] + sum1[i][1] + sum1[i+1][1], 107 sum0[i][2] + sum0[i+1][2] + sum1[i][2] + sum1[i+1][2], 108 sum0[i][3] + sum0[i+1][3] + sum1[i][3] + sum1[i+1][3] ); 109 return ssim; 110} 111 112float ssim_plane( 113 pixel *pix1, intptr_t stride1, 114 pixel *pix2, intptr_t stride2, 115 int width, int height, void *buf, int *cnt ) 116{ 117 int z = 0; 118 int x, y; 119 float ssim = 0.0; 120 int (*sum0)[4] = buf; 121 int (*sum1)[4] = sum0 + (width >> 2) + 3; 122 width >>= 2; 123 height >>= 2; 124 for( y = 1; y < height; y++ ) 125 { 126 for( ; z <= y; z++ ) 127 { 128 FFSWAP( void*, sum0, sum1 ); 129 for( x = 0; x < width; x+=2 ) 130 ssim_4x4x2_core( &pix1[4*(x+z*stride1)], stride1, &pix2[4*(x+z*stride2)], stride2, &sum0[x] ); 131 } 132 for( x = 0; x < width-1; x += 4 ) 133 ssim += ssim_end4( sum0+x, sum1+x, FFMIN(4,width-x-1) ); 134 } 135// *cnt = (height-1) * (width-1); 136 return ssim / ((height-1) * (width-1)); 137} 138 139 140uint64_t ssd_plane( const uint8_t *pix1, const uint8_t *pix2, int size ) 141{ 142 uint64_t ssd = 0; 143 int i; 144 for( i=0; i<size; i++ ) 145 { 146 int d = pix1[i] - pix2[i]; 147 ssd += d*d; 148 } 149 return ssd; 150} 151 152static double ssd_to_psnr( uint64_t ssd, uint64_t denom ) 153{ 154 return -10*log((double)ssd/(denom*255*255))/log(10); 155} 156 157static double ssim_db( double ssim, double weight ) 158{ 159 return 10*(log(weight)/log(10)-log(weight-ssim)/log(10)); 160} 161 162static void print_results(uint64_t ssd[3], double ssim[3], int frames, int w, int h) 163{ 164 printf( "PSNR Y:%.3f U:%.3f V:%.3f All:%.3f | ", 165 ssd_to_psnr( ssd[0], (uint64_t)frames*w*h ), 166 ssd_to_psnr( ssd[1], (uint64_t)frames*w*h/4 ), 167 ssd_to_psnr( ssd[2], (uint64_t)frames*w*h/4 ), 168 ssd_to_psnr( ssd[0] + ssd[1] + ssd[2], (uint64_t)frames*w*h*3/2 ) ); 169 printf( "SSIM Y:%.5f U:%.5f V:%.5f All:%.5f (%.5f)", 170 ssim[0] / frames, 171 ssim[1] / frames, 172 ssim[2] / frames, 173 (ssim[0]*4 + ssim[1] + ssim[2]) / (frames*6), 174 ssim_db(ssim[0] * 4 + ssim[1] + ssim[2], frames*6)); 175} 176 177int main(int argc, char* argv[]) 178{ 179 FILE *f[2]; 180 uint8_t *buf[2], *plane[2][3]; 181 int *temp; 182 uint64_t ssd[3] = {0,0,0}; 183 double ssim[3] = {0,0,0}; 184 int frame_size, w, h; 185 int frames, seek; 186 int i; 187 188 if( argc<4 || 2 != sscanf(argv[3], "%dx%d", &w, &h) ) 189 { 190 printf("tiny_ssim <file1.yuv> <file2.yuv> <width>x<height> [<seek>]\n"); 191 return -1; 192 } 193 194 f[0] = fopen(argv[1], "rb"); 195 f[1] = fopen(argv[2], "rb"); 196 sscanf(argv[3], "%dx%d", &w, &h); 197 198 if (w<=0 || h<=0 || w*(int64_t)h >= INT_MAX/3 || 2LL*w+12 >= INT_MAX / sizeof(*temp)) { 199 fprintf(stderr, "Dimensions are too large, or invalid\n"); 200 return -2; 201 } 202 203 frame_size = w*h*3LL/2; 204 for( i=0; i<2; i++ ) 205 { 206 buf[i] = malloc(frame_size); 207 plane[i][0] = buf[i]; 208 plane[i][1] = plane[i][0] + w*h; 209 plane[i][2] = plane[i][1] + w*h/4; 210 } 211 temp = malloc((2*w+12)*sizeof(*temp)); 212 seek = argc<5 ? 0 : atoi(argv[4]); 213 fseek(f[seek<0], seek < 0 ? -seek : seek, SEEK_SET); 214 215 for( frames=0;; frames++ ) 216 { 217 uint64_t ssd_one[3]; 218 double ssim_one[3]; 219 if( fread(buf[0], frame_size, 1, f[0]) != 1) break; 220 if( fread(buf[1], frame_size, 1, f[1]) != 1) break; 221 for( i=0; i<3; i++ ) 222 { 223 ssd_one[i] = ssd_plane ( plane[0][i], plane[1][i], w*h>>2*!!i ); 224 ssim_one[i] = ssim_plane( plane[0][i], w>>!!i, 225 plane[1][i], w>>!!i, 226 w>>!!i, h>>!!i, temp, NULL ); 227 ssd[i] += ssd_one[i]; 228 ssim[i] += ssim_one[i]; 229 } 230 231 printf("Frame %d | ", frames); 232 print_results(ssd_one, ssim_one, 1, w, h); 233 printf(" \r"); 234 fflush(stdout); 235 } 236 237 if( !frames ) return 0; 238 239 printf("Total %d frames | ", frames); 240 print_results(ssd, ssim, frames, w, h); 241 printf("\n"); 242 243 return 0; 244} 245