/*
  * originally by Andreas Öman (andoma)
  * some changes by Alexander Strange
  */
 
 #include <string.h>
 #include <stdlib.h>
 #include <inttypes.h>
 #include <stdio.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 

 #if HAVE_UNISTD_H
 #include <unistd.h>
 #endif

 
 int
 main(int argc, char **argv)
 {
     int fd[2];
     int print_pixels = 0;
     int dump_blocks = 0;
 
     int width;
     int height;
     int to_skip = 0;
 
     if (argc < 6) {
         fprintf(stderr, "%s [YUV file 1] [YUV file 2] width height pixelcmp|blockdump (# to skip)\n", argv[0]);
         return 1;
     }
 
     width  = atoi(argv[3]);
     height = atoi(argv[4]);
     if (argc > 6)
         to_skip = atoi(argv[6]);
 
     uint8_t *Y[2], *C[2][2];
     int i, v, c, p;
     int lsiz = width * height;
     int csiz = width * height / 4;
     int x, y;
     int cwidth = width / 2;
     int fr = to_skip;
     int mb;
     char *mberrors;
     int mb_x, mb_y;
     uint8_t *a;
     uint8_t *b;
     int die = 0;
 
     print_pixels = strstr(argv[5], "pixelcmp") ? 1 : 0;
     dump_blocks  = strstr(argv[5], "blockdump") ? 1 : 0;
 
     for(i = 0; i < 2; i++) {
         Y[i] = malloc(lsiz);
         C[0][i] = malloc(csiz);
         C[1][i] = malloc(csiz);
 
         fd[i] = open(argv[1 + i], O_RDONLY);
         if(fd[i] == -1) {
             perror("open");
             exit(1);
         }
         fcntl(fd[i], F_NOCACHE, 1);
 
         if (to_skip)
             lseek(fd[i], to_skip * (lsiz + 2*csiz), SEEK_SET);
     }
 
     mb_x = width / 16;
     mb_y = height / 16;
 
     mberrors = malloc(mb_x * mb_y);
 
     while(!die) {
         memset(mberrors, 0, mb_x * mb_y);
 
         printf("Loading frame %d\n", ++fr);
 
         for(i = 0; i < 2; i++) {
             v = read(fd[i], Y[i], lsiz);
             if(v != lsiz) {
                 fprintf(stderr, "Unable to read Y from file %d, exiting\n", i + 1);
                 return 1;
             }
         }
 
 
         for(c = 0; c < lsiz; c++) {
             if(Y[0][c] != Y[1][c]) {
                 x = c % width;
                 y = c / width;
 
                 mb = x / 16 + (y / 16) * mb_x;
 
                 if(print_pixels)
                     printf("Luma diff 0x%02x != 0x%02x at pixel (%4d,%-4d) mb(%d,%d) #%d\n",
                            Y[0][c],
                            Y[1][c],
                            x, y,
                            x / 16,
                            y / 16,
                            mb);
 
                 mberrors[mb] |= 1;
             }
         }
 
         /* Chroma planes */
 
         for(p = 0; p < 2; p++) {
 
             for(i = 0; i < 2; i++) {
                 v = read(fd[i], C[p][i], csiz);
                 if(v != csiz) {
                     fprintf(stderr, "Unable to read %c from file %d, exiting\n",
                             "UV"[p], i + 1);
                     return 1;
                 }
             }
 
             for(c = 0; c < csiz; c++) {
                 if(C[p][0][c] != C[p][1][c]) {
                     x = c % cwidth;
                     y = c / cwidth;
 
                     mb = x / 8 + (y / 8) * mb_x;
 
                     mberrors[mb] |= 2 << p;
 
                     if(print_pixels)
 
                         printf("c%c diff 0x%02x != 0x%02x at pixel (%4d,%-4d) "
                                "mb(%3d,%-3d) #%d\n",
                                p ? 'r' : 'b',
                                C[p][0][c],
                                C[p][1][c],
 
                                x, y,
                                x / 8,
                                y / 8,
                                x / 8 + y / 8 * cwidth / 8);
                 }
             }
         }
 
         for(i = 0; i < mb_x * mb_y; i++) {
             x = i % mb_x;
             y = i / mb_x;
 
             if(mberrors[i]) {
                 die = 1;
 
                 printf("MB (%3d,%-3d) %4d %d %c%c%c damaged\n",
                        x, y, i, mberrors[i],
                        mberrors[i] & 1 ? 'Y' : ' ',
                        mberrors[i] & 2 ? 'U' : ' ',
                        mberrors[i] & 4 ? 'V' : ' ');
 
                 if(dump_blocks) {
                     a = Y[0] + x * 16 + y * 16 * width;
                     b = Y[1] + x * 16 + y * 16 * width;
 
                     for(y = 0; y < 16; y++) {
                         printf("%c ", "TB"[y&1]);
                         for(x = 0; x < 16; x++)
                             printf("%02x%c", a[x + y * width],
                                    a[x + y * width] != b[x + y * width] ? '<' : ' ');
 
                         printf("| ");
                         for(x = 0; x < 16; x++)
                             printf("%02x%c", b[x + y * width],
                                    a[x + y * width] != b[x + y * width] ? '<' : ' ');
 
                         printf("\n");
                     }
                 }
             }
         }
     }
 
     return 0;
 }