Util/JpegHeader.cs

   1 namespace Beagle.Util {
   2
   3 public class JpegHeader {
   4         public enum JpegMarker {
   5                 // The Following tags are listed as containing the content within the
   6                 // marker itself and the data is stored in the two bytes that would
   7                 // otherwise hold the length.
   8                 Tem = 0x01, // no length, ignore
   9                 Rst0 = 0xd0,  // RstN used for resync, ignore
  10                 Rst1 = 0xd1,
  11                 Rst2 = 0xd2,
  12                 Rst3 = 0xd3,
  13                 Rst4 = 0xd4,
  14                 Rst5 = 0xd5,
  15                 Rst6 = 0xd6,
  16                 Rst7 = 0xd7,
  17
  18                 Sof0 = 0xc0, // SOFn Start of frame 0-1 common
  19                 Sof1 = 0xc1,
  20                 Sof2 = 0xc2,
  21                 Sof3 = 0xc3,
  22
  23                 Dht = 0xc4,  // Define Huffman Table
  24
  25                 Sof5 = 0xc5,
  26                 Sof6 = 0xc6,
  27                 Sof7 = 0xc7,
  28
  29                 Jpg = 0xc8, // reserved
  30
  31                 Sof9 = 0xc9,
  32                 Sof10 = 0xc10,
  33                 Sof11 = 0xc11,
  34                 Sof12 = 0xc12,
  35                 Sof13 = 0xc13,
  36                 Sof14 = 0xc14,
  37                 Sof15 = 0xc15,
  38
  39                 // These tags all consist of a marker and then a length.
  40
  41                 // These are the major structure tags.
  42                 Soi  = 0xd8,  // Start of Image
  43                 Eoi  = 0xd9,  // End of Image
  44                 Sos  = 0xda,  // Start of Scan
  45
  46                 Dnl = 0xdc,
  47                 Dri = 0xdd,  // Define restart interval
  48                 Dhp = 0xde,
  49                 Exp = 0xdf,
  50
  51                 Dqt = 0xdb, // Define Quantization Table
  52
  53                 // These are the app marker tags that contain the application metadata
  54                 // in its various forms.
  55                 App0 = 0xe0,  // AppN Markers for application data
  56                 App1 = 0xe1,
  57                 App2 = 0xe2,
  58                 App3 = 0xe3,
  59                 App4 = 0xe4,
  60                 App5 = 0xe5,
  61                 App6 = 0xe6,
  62                 App7 = 0xe7,
  63                 App8 = 0xe8,
  64                 App9 = 0xe9,
  65                 App10 = 0xea,
  66                 App11 = 0xeb,
  67                 App12 = 0xec,
  68                 App13 = 0xed,
  69                 App14 = 0xee,
  70                 App15 = 0xef,
  71
  72                 Jpg0 = 0xf0,
  73                 Jpg1 = 0xf1,
  74                 Jpg2 = 0xf2,
  75                 Jpg3 = 0xf3,
  76                 Jpg4 = 0xf4,
  77                 Jpg5 = 0xf5,
  78                 Jpg6 = 0xf6,
  79                 Jpg7 = 0xf7,
  80                 Jpg8 = 0xf8,
  81                 Jpg9 = 0xf9,
  82                 Jpg10 = 0xfa,
  83                 Jpg11 = 0xfb,
  84                 Jpg12 = 0xfc,
  85                 Jpg13 = 0xfd,
  86
  87                 Com = 0xfe // Comment
  88         }
  89
  90         public class Marker {
  91                 public Marker (JpegMarker type, byte [] data, long position)
  92                 {
  93                         this.Type = type;
  94                         this.Data = data;
  95                         this.Position = position;
  96                 }
  97
  98                 public JpegMarker Type;
  99                 public byte [] Data;
 100                 public long Position;
 101         }
 102
 103         public byte [] GetRawXmp ()
 104         {
 105                 return this.GetRaw ("http://ns.adobe.com/xap/1.0/");
 106         }
 107
 108         public byte [] GetRawExif ()
 109         {
 110                 return this.GetRaw ("Exif");
 111         }
 112         public byte [] GetRawJfif ()
 113         {
 114                 return this.GetRaw ("JFIF");
 115         }
 116
 117         public byte [] GetRawIcc ()
 118         {
 119                 return this.GetRaw ("ICC_PROFILE");
 120         }
 121
 122         public byte [] GetRaw (string name)
 123         {
 124                 Marker m = (Marker)app_marker_hash [name];
 125                 if (m != null)
 126                         return m.Data;
 127                 else
 128                         return null;
 129         }
 130
 131         private void AddNamed (Marker m)
 132         {
 133                 int j;
 134                 for (j = 0; j < m.Data.Length; j++) {
 135                         if (m.Data [j] == 0x00)
 136                                 break;
 137                 }
 138
 139                 string header = System.Text.Encoding.ASCII.GetString (m.Data, 0, j);
 140                 app_marker_hash [header] = m;
 141                 //System.Console.WriteLine (header);
 142         }
 143
 144         System.Collections.Hashtable app_marker_hash = new System.Collections.Hashtable ();
 145         System.Collections.ArrayList marker_list = new System.Collections.ArrayList ();
 146
 147         public JpegHeader (string filename)
 148         {
 149                 //System.Console.WriteLine ("opening {0}", filename);
 150                 System.IO.FileStream stream = new System.IO.FileStream (filename, System.IO.FileMode.Open);
 151                 LoadFromStream (stream);
 152                 stream.Close ();
 153         }
 154
 155         public JpegHeader (System.IO.Stream stream)
 156         {
 157                 LoadFromStream (stream);
 158         }
 159
 160         private void LoadFromStream (System.IO.Stream stream)
 161         {
 162                 byte [] length_data = new byte [2];
 163
 164                 if (stream.ReadByte () != 0xff || (JpegMarker)stream.ReadByte () != JpegMarker.Soi)
 165                         throw new System.Exception ("Invalid file Type, not a JPEG file");
 166
 167                 bool at_image = false;
 168                 while (!at_image) {
 169                         int i = 0;
 170                         JpegMarker marker;
 171
 172                         // 0xff can be used as padding between markers, ignore it all
 173                         // of it for now.
 174                         do {
 175                                 marker = (JpegMarker)stream.ReadByte ();
 176                                 i++;
 177                         } while (marker == (JpegMarker)0xff);
 178
 179
 180                         if (i < 2)
 181                                 throw new System.Exception ("Invalid Marker");
 182
 183                         long position = stream.Position - 1;
 184
 185                         // FIXME use real byteswapping later
 186                         if (System.BitConverter.IsLittleEndian) {
 187                                 length_data [1] = (byte)stream.ReadByte ();
 188                                 length_data [0] = (byte)stream.ReadByte ();
 189                         } else {
 190                                 length_data [0] = (byte)stream.ReadByte ();
 191                                 length_data [1] = (byte)stream.ReadByte ();
 192                         }
 193
 194                         ushort length = System.BitConverter.ToUInt16 (length_data, 0);
 195                         //System.Console.WriteLine ("Marker {0} Length = {1}", marker.ToString (), length);
 196
 197                         if (length < 2)
 198                                 throw new System.Exception ("Invalid Marker length");
 199
 200                         length -= 2;
 201
 202                         switch (marker) {
 203                         case JpegMarker.App0:
 204                         case JpegMarker.App1:
 205                         case JpegMarker.App2:
 206                         case JpegMarker.App3:
 207                         case JpegMarker.App4:
 208                         case JpegMarker.App5:
 209                         case JpegMarker.App6:
 210                         case JpegMarker.App7:
 211                         case JpegMarker.App8:
 212                         case JpegMarker.App9:
 213                         case JpegMarker.App10:
 214                         case JpegMarker.App11:
 215                         case JpegMarker.App12:
 216                         case JpegMarker.App13:
 217                         case JpegMarker.App14:
 218                         case JpegMarker.App15:
 219                                 byte [] data = new byte [length];
 220                                 if (stream.Read (data, 0, length) != length)
 221                                         throw new System.Exception ("Incomplete Marker");
 222
 223                                 Marker m = new Marker (marker, data, position);
 224                                 marker_list.Add (m);
 225                                 this.AddNamed (m);
 226                                 break;
 227                         case JpegMarker.Rst0:
 228                         case JpegMarker.Rst1:
 229                         case JpegMarker.Rst2:
 230                         case JpegMarker.Rst3:
 231                         case JpegMarker.Rst4:
 232                         case JpegMarker.Rst5:
 233                         case JpegMarker.Rst6:
 234                         case JpegMarker.Rst7:
 235                         case JpegMarker.Tem:
 236                                 // These markers have no data it is in length_data
 237
 238                                 marker_list.Add (new Marker (marker, length_data, position));
 239                                 break;
 240                         default:
 241                                 byte [] d = new byte [length];
 242                                 if (stream.Read (d, 0, length) != length)
 243                                         throw new System.Exception ("Incomplete Marker");
 244
 245                                 marker_list.Add (new Marker (marker, d, position));
 246                                 break;
 247                         }
 248
 249                         if (marker == JpegMarker.Sos)
 250                                 at_image = true;
 251                 }
 252         }
 253
 254 #if false
 255         public static int Main (string [] args)
 256         {
 257                 JpegHeader data = new JpegHeader (args [0]);
 258                 byte [] value = data.GetRawXmp ();
 259
 260                 if (value != null) {
 261                         string xml = System.Text.Encoding.UTF8.GetString (value, 29, value.Length - 29);
 262                         System.Console.WriteLine (xml);
 263                 }
 264
 265                 value = data.GetRaw ("ICC_PROFILE");
 266                 if (value != null) {
 267                         System.IO.FileStream stream = new System.IO.FileStream ("profile.icc", System.IO.FileMode.Create);
 268                         stream.Write (value, 12, value.Length - 12);
 269                         stream.Close ();
 270                 }
 271
 272                 value = data.GetRawExif ();
 273                 if (value != null) {
 274                         System.IO.MemoryStream stream = new System.IO.MemoryStream (value, 6, value.Length - 6);
 275                         Tiff.Header tiff = new Tiff.Header (stream);
 276                         tiff.Dump ();
 277                 }
 278
 279                 return 0;
 280         }
 281 #endif
 282 }
 283
 284 }