camlibs/sipix/xjpeg.c

   1 /* Simple JPEG tag extractor and viewer. (c) Marcus Meissner 2003, LGPL */
   2 #include <stdio.h>
   3 #include <unistd.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6
   7 #define APP0    0xe0
   8 #define APP1    0xe1
   9 #define APP2    0xe2
  10 #define DHT     0xc4
  11 #define SOI     0xd8
  12 #define DQT     0xdb
  13 #define SOF0    0xc0
  14 #define SOS     0xda
  15 #define COM     0xfe
  16
  17 static int
  18 rb(int suppress) {
  19         unsigned char c;
  20
  21         if (1!=read(fileno(stdin),&c,1))
  22                 return -1;
  23         if (!suppress)
  24                 fprintf(stderr,"%02x",c);
  25         return c;
  26 }
  27
  28 static int
  29 rd(int len, char *data) {
  30         unsigned int c,i;
  31
  32         for (i=0;i<len;i++) {
  33                 c = rb(1);
  34                 if (c == -1) return -1;
  35                 if (c == 0xff) c = rb(1);
  36                 if (c == -1) return -1;
  37                 data[i] = c;
  38         }
  39         return len;
  40 }
  41
  42 static int
  43 getmarker(void) {
  44         int c;
  45
  46         c = rb(0);
  47         if (c == -1) return -1;
  48         if (c!=0xff) return -1;
  49         c = rb(0);
  50         return c;
  51 }
  52
  53 static int
  54 getlength(void) {
  55         int x1,x2;
  56
  57         x1 = rb(1);
  58         if (x1 == -1) return -1;
  59         x2 = rb(1);
  60         if (x2 == -1) return -1;
  61         x1 =  (x1 << 8) | x2;
  62         fprintf(stderr,"(%d)",x1);
  63         return x1;
  64 }
  65
  66 static int
  67 skipdata(int len, int suppress) {
  68         int x,i;
  69
  70         for (i=0;i<len;i++) {
  71                 x = rb(suppress);
  72                 if (x == -1)
  73                         return x;
  74                 if (x == 0xff) {
  75                         x = rb(suppress);
  76                         if (x == -1)
  77                                 return x;
  78                 }
  79         }
  80         return 1;
  81 }
  82
  83 static int
  84 haslength(int marker) {
  85         switch (marker) {
  86         case SOI:       return 0;
  87         case APP0:      return 1;
  88         case APP1:      return 1;
  89         case APP2:      return 1;
  90         case DHT:       return 1;
  91         case SOS:       return 1;
  92         case DQT:       return 1;
  93         case COM:       return 1;
  94         default:        return 1;
  95         }
  96 }
  97
  98 static int
  99 print_jfif() {
 100         int major, minor, density, x, y, r, tx, ty ;
 101         r = rb(1); if (r == -1) return -1;
 102
 103         major = rb(1);
 104         if (major == -1) return -1;
 105         minor = rb(1);
 106         if (minor == -1) return -1;
 107         density = rb(1);
 108         if (density == -1) return -1;
 109
 110         x = rb(1); if (x == -1) return -1;
 111         r = rb(1); if (r == -1) return -1;
 112         x = (x << 8) | r;
 113
 114         y = rb(1); if (y == -1) return -1;
 115         r = rb(1); if (r == -1) return -1;
 116         y = (y << 8) | r;
 117         tx = rb(1); if (tx == -1) return -1;
 118         ty = rb(1); if (ty == -1) return -1;
 119         fprintf(stderr,"JFIF v%d.%d, dens %d, %dx%d, tn %dx%d\n", major, minor, density, x, y, tx, ty);
 120         return skipdata(tx * ty * 3,1);
 121 }
 122
 123 int
 124 main(int argc, char **argv) {
 125         int m, len;
 126
 127         m = getmarker();
 128         if (m != SOI) {
 129                 fprintf(stderr,":unknown, aborting.\n");
 130                 return 1;
 131         }
 132         fprintf(stderr,":SOI\n");
 133         while (1) {
 134                 m = getmarker();
 135                 if (m == -1) {
 136                         fprintf(stderr,":Error, end of file, aborting.\n");
 137                         break;
 138                 }
 139                 if (haslength(m))
 140                         len = getlength();
 141                 else
 142                         len = 0;
 143                 switch (m) {
 144                 case COM: {
 145                         char *comment;
 146
 147                         comment = malloc(len - 2 + 1);
 148                         comment[len-2]='\0';
 149                         if (-1 == rd(len - 2, comment))
 150                                 break;
 151                         fprintf(stderr,":COM(%s)\n",comment);
 152                         break;
 153                 }
 154                 case SOS: {
 155                         int i,ns,ss,se,ahl,cs,td;
 156
 157                         ns = rb(1);if (ns == -1) break;
 158                         fprintf(stderr,":SOS ");
 159                         for (i=0;i<ns;i++) {
 160                                 cs = rb(1);if (cs == -1) break;
 161                                 td = rb(1);if (td == -1) break;
 162                                 fprintf(stderr,"[%d,%d:%d]",cs,(td>>4),td&0xf);
 163                         }
 164                         ss = rb(1); if (ss == -1) break;
 165                         se = rb(1); if (se == -1) break;
 166                         ahl = rb(1); if (ahl == -1) break;
 167                         fprintf(stderr,"ss=%d, se=%d, h=%d,l=%d\n",ss,se,(ahl>>4),ahl&0xf);
 168                         break;
 169                 }
 170                 case SOF0: {
 171                         int bitcnt,x,y,nf,i,c,hv,tq;
 172                         m = rb(1); if (m == -1) break;
 173                         bitcnt = m;
 174                         y = rb(1); if (y == -1) break;
 175                         m = rb(1); if (m == -1) break;
 176                         y = (y<<8) | m;
 177                         x = rb(1); if (x == -1) break;
 178                         m = rb(1); if (m == -1) break;
 179                         x = (x<<8) | m;
 180                         nf = rb(1); if (nf == -1) break;
 181
 182                         fprintf(stderr,":SOF0,bitcnt=%d,x=%d,y=%d:\n",bitcnt,x,y);
 183                         for (i=0;i<nf;i++) {
 184                                 c = rb(1); if (c == -1) break;
 185                                 hv = rb(1); if (hv == -1) break;
 186                                 tq = rb(1); if (tq == -1) break;
 187                                 fprintf(stderr,"\t %02x = %d:%d, tq=%d\n",c,(hv>>4),hv&0xf,tq);
 188                         }
 189                         break;
 190                 }
 191                 case DHT: {
 192                         m = rb(1);
 193                         if (m == -1) break;
 194                         fprintf(stderr,":DHT(0x%02x)\n",m);
 195                         skipdata(len - 2 - 1,1);
 196                         break;
 197                 }
 198                 case DQT: {
 199                         fprintf(stderr,":DQT\n");
 200                         skipdata(len-2,1);
 201                         break;
 202                 }
 203                 case APP1: case APP2:
 204                 case APP0: {
 205                         char name[5];
 206                         fprintf(stderr,":APP0(");
 207                         if (-1==rd(4,name))
 208                                 break;
 209                         name[4] = '\0';
 210                         fprintf(stderr,"%s):", name);
 211                         if (!strcmp(name,"JFIF")) {
 212                                 print_jfif();
 213                         } else {
 214                                 if (-1==skipdata(len - 2 - 4,0)) {
 215                                         break;
 216                                 }
 217                                 fprintf(stderr,"\n");
 218                         }
 219                         break;
 220                 }
 221                 default:
 222                         fprintf(stderr,":Unknown marker\n");
 223                         if (len) {
 224                                 if (-1==skipdata(len - 2,0)) {
 225                                         break;
 226                                 }
 227                                 fprintf(stderr,"\n");
 228                         }
 229                         break;
 230                 }
 231         }
 232         return 0;
 233 }