epan/dissectors/packet-mpeg1.c

   1 /* packet-mpeg1.c
   2  *
   3  * Routines for RFC 2250 MPEG-1 dissection
   4  *
   5  * $Id$
   6  *
   7  * Copyright 2001,
   8  * Francisco Javier Cabello Torres, <fjcabello@vtools.es>
   9  *
  10  * Wireshark - Network traffic analyzer
  11  * By Gerald Combs <gerald@wireshark.org>
  12  * Copyright 1998 Gerald Combs
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License
  16  * as published by the Free Software Foundation; either version 2
  17  * of the License, or (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  27  */
  28
  29 /*
  30  * This dissector tries to dissect the MPEG-1 video streams.
  31  */
  32
  33
  34 #ifdef HAVE_CONFIG_H
  35 # include "config.h"
  36 #endif
  37
  38 #include <glib.h>
  39 #include <epan/packet.h>
  40
  41 #include <epan/rtp_pt.h>
  42
  43 #define RTP_MPG_MBZ(word) ( word >> 11)
  44 #define RTP_MPG_T(word)   ( (word >> 10) & 1 )
  45 #define RTP_MPG_TR(word)   ( word & 0x3ff )
  46
  47 #define RTP_MPG_AN(octet) ( octet >> 7)
  48 #define RTP_MPG_N(octet)  ( (octet >> 6) & 1 )
  49 #define RTP_MPG_S(octet)  ( (octet >> 5) & 1 )
  50 #define RTP_MPG_B(octet)  ( (octet >> 4) & 1 )
  51 #define RTP_MPG_E(octet)  ( (octet >> 3) & 1 )
  52 #define RTP_MPG_P(octet)  ( octet & 7 )
  53
  54 #define RTP_MPG_FBV(octet) ( (octet >> 7) & 1 )
  55 #define RTP_MPG_BFC(octet) ( (octet >> 4) & 7 )
  56 #define RTP_MPG_FFV(octet) ( (octet >> 3) & 1 )
  57 #define RTP_MPG_FFC(octet) (  octet & 7 )
  58
  59
  60 /* MPEG1 header fields             */
  61
  62
  63 static int proto_mpg          = -1;
  64
  65 static int hf_rtp_mpg_mbz     = -1;
  66 static int hf_rtp_mpg_T       = -1;
  67 static int hf_rtp_mpg_tr      = -1;
  68 static int hf_rtp_mpg_an      = -1;
  69 static int hf_rtp_mpg_n       = -1;
  70 static int hf_rtp_mpg_s       = -1;
  71 static int hf_rtp_mpg_b       = -1;
  72 static int hf_rtp_mpg_e       = -1;
  73 static int hf_rtp_mpg_p       = -1;
  74
  75
  76 static int hf_rtp_mpg_fbv     = -1;
  77 static int hf_rtp_mpg_bfc     = -1;
  78 static int hf_rtp_mpg_ffv     = -1;
  79 static int hf_rtp_mpg_ffc     = -1;
  80 static int hf_rtp_mpg_data    = -1;
  81
  82
  83
  84 /* MPEG-1 fields defining a sub tree */
  85 static gint ett_mpg           = -1;
  86
  87 static const value_string rtp_mpg_picture_types_vals[] =
  88 {
  89         { 0, "Forbidden" },
  90         { 1, "I-Picture" },
  91         { 2, "P-Picture" },
  92         { 3, "B-Picture" },
  93         { 4, "D-Picture" },
  94         { 5, "reserved" },
  95         { 6, "reserved" },
  96         { 7, "reserved" },
  97         { 0, NULL },
  98 };
  99
 100 static void
 101 dissect_mpeg1( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
 102 {
 103         proto_item *ti            = NULL;
 104         proto_tree *mpg_tree     = NULL;
 105         unsigned int offset       = 0;
 106
 107         guint8      octet;
 108         guint16     word;
 109
 110
 111         guint16     mpg_mbz;
 112         guint16     mpg_T;
 113         guint16     mpg_tr;
 114         guint16     mpg_an;
 115         guint16     mpg_n;
 116         gboolean    mpg_s;
 117         gboolean    mpg_b;
 118         gboolean    mpg_e;
 119         guint16     mpg_p;
 120         guint16     mpg_fbv;
 121         guint16     mpg_bfc;
 122         guint16     mpg_ffv;
 123         guint16     mpg_ffc;
 124
 125         col_set_str(pinfo->cinfo, COL_PROTOCOL, "MPEG-1");
 126
 127         col_set_str(pinfo->cinfo, COL_INFO, "MPEG-1 message");
 128
 129         /* Get MPEG-1  fields */
 130
 131         word  =   tvb_get_guint8( tvb, offset  );
 132         word  = (word << 8) | tvb_get_guint8( tvb, offset +1 );
 133         mpg_mbz = RTP_MPG_MBZ(word);
 134         mpg_T   = RTP_MPG_T(word);
 135         mpg_tr  = RTP_MPG_TR(word);
 136
 137         octet = tvb_get_guint8( tvb, offset + 2 );
 138         mpg_an  = RTP_MPG_AN(octet);
 139         mpg_n   = RTP_MPG_N(octet);
 140         mpg_s   = RTP_MPG_S(octet);
 141         mpg_b   = RTP_MPG_B(octet);
 142         mpg_e   = RTP_MPG_E(octet);
 143         mpg_p   = RTP_MPG_P(octet);
 144
 145         octet = tvb_get_guint8( tvb, offset + 3 );
 146
 147         mpg_fbv   = RTP_MPG_FBV(octet);
 148         mpg_bfc   = RTP_MPG_BFC(octet);
 149         mpg_ffv   = RTP_MPG_FFV(octet);
 150         mpg_ffc   = RTP_MPG_FFC(octet);
 151
 152
 153         if ( tree )
 154           {
 155             ti = proto_tree_add_item( tree, proto_mpg, tvb, offset, -1, ENC_NA );
 156             mpg_tree = proto_item_add_subtree( ti, ett_mpg );
 157
 158             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_mbz, tvb, offset, 1, mpg_mbz );
 159             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_T  , tvb, offset, 1, mpg_T );
 160             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_tr , tvb, offset, 2, mpg_tr );
 161             offset += 2;
 162             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_an, tvb, offset, 1, mpg_an );
 163             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_n , tvb, offset, 1, mpg_n );
 164             proto_tree_add_boolean( mpg_tree, hf_rtp_mpg_s , tvb, offset, 1, mpg_s );
 165             proto_tree_add_boolean( mpg_tree, hf_rtp_mpg_b , tvb, offset, 1, mpg_b );
 166             proto_tree_add_boolean( mpg_tree, hf_rtp_mpg_e , tvb, offset, 1, mpg_e );
 167
 168             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_p, tvb , offset, 1, mpg_p );
 169             offset += 1;
 170
 171             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_fbv, tvb, offset, 1, mpg_fbv );
 172             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_bfc, tvb, offset, 1, mpg_bfc );
 173             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_ffv, tvb, offset, 1, mpg_ffv );
 174             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_ffc, tvb, offset, 1, mpg_ffc );
 175             offset += 1;
 176
 177             /* The rest of the packet is the MPEG-1 stream */
 178             proto_tree_add_item( mpg_tree, hf_rtp_mpg_data, tvb, offset, -1, ENC_NA );
 179
 180           }
 181 }
 182
 183 void
 184 proto_register_mpeg1(void)
 185 {
 186         static hf_register_info hf[] =
 187         {
 188                 {
 189                         &hf_rtp_mpg_mbz,
 190                         {
 191                                 "MBZ",
 192                                 "rtp.payload_mpeg_mbz",
 193                                 FT_UINT16,
 194                                 BASE_DEC,
 195                                 NULL,
 196                                 0x0,
 197                                 NULL, HFILL
 198                         }
 199                 },
 200                 {
 201                         &hf_rtp_mpg_T,
 202                         {
 203                                 "T",
 204                                 "rtp.payload_mpeg_T",
 205                                 FT_UINT16,
 206                                 BASE_DEC,
 207                                 NULL,
 208                                 0x0,
 209                                 NULL, HFILL
 210                         }
 211                 },
 212                 {
 213                         &hf_rtp_mpg_tr,
 214                         {
 215                                 "Temporal Reference",
 216                                 "rtp.payload_mpeg_tr",
 217                                 FT_UINT16,
 218                                 BASE_DEC,
 219                                 NULL,
 220                                 0x0,
 221                                 NULL, HFILL
 222                         }
 223                 },
 224                 {
 225                         &hf_rtp_mpg_an,
 226                         {
 227                                 "AN",
 228                                 "rtp.payload_mpeg_an",
 229                                 FT_UINT16,
 230                                 BASE_DEC,
 231                                 NULL,
 232                                 0x0,
 233                                 NULL, HFILL
 234                         }
 235                 },
 236
 237                 {
 238                         &hf_rtp_mpg_n,
 239                         {
 240                                 "New Picture Header",
 241                                 "rtp.payload_mpeg_n",
 242                                 FT_UINT16,
 243                                 BASE_DEC,
 244                                 NULL,
 245                                 0x0,
 246                                 NULL, HFILL
 247                         }
 248                 },
 249
 250                 {
 251                         &hf_rtp_mpg_s,
 252                         {
 253                                 "Sequence Header",
 254                                 "rtp.payload_mpeg_s",
 255                                 FT_BOOLEAN,
 256                                 BASE_NONE,
 257                                 NULL,
 258                                 0x0,
 259                                 NULL, HFILL
 260                         }
 261                 },
 262
 263                 {
 264                         &hf_rtp_mpg_b,
 265                         {
 266                                 "Beginning-of-slice",
 267                                 "rtp.payload_mpeg_b",
 268                                 FT_BOOLEAN,
 269                                 BASE_NONE,
 270                                 NULL,
 271                                 0x0,
 272                                 NULL, HFILL
 273                         }
 274                 },
 275
 276                 {
 277                         &hf_rtp_mpg_e,
 278                         {
 279                                 "End-of-slice",
 280                                 "rtp.payload_mpeg_an",
 281                                 FT_BOOLEAN,
 282                                 BASE_NONE,
 283                                 NULL,
 284                                 0x0,
 285                                 NULL, HFILL
 286                         }
 287                 },
 288
 289                 {
 290                         &hf_rtp_mpg_p,
 291                         {
 292                                 "Picture type",
 293                                 "rtp.payload_mpeg_p",
 294                                 FT_UINT16,
 295                                 BASE_DEC,
 296                                 VALS(rtp_mpg_picture_types_vals),
 297                                 0x0,
 298                                 NULL, HFILL
 299                         }
 300                 },
 301
 302                 {
 303                         &hf_rtp_mpg_fbv,
 304                         {
 305                                 "FBV",
 306                                 "rtp.payload_mpeg_fbv",
 307                                 FT_UINT16,
 308                                 BASE_DEC,
 309                                 NULL,
 310                                 0x0,
 311                                 NULL, HFILL
 312                         }
 313                 },
 314
 315                 {
 316                         &hf_rtp_mpg_bfc,
 317                         {
 318                                 "BFC",
 319                                 "rtp.payload_mpeg_bfc",
 320                                 FT_UINT16,
 321                                 BASE_DEC,
 322                                 NULL,
 323                                 0x0,
 324                                 NULL, HFILL
 325                         }
 326                 },
 327                 {
 328                         &hf_rtp_mpg_ffv,
 329                         {
 330                                 "FFV",
 331                                 "rtp.payload_mpeg_ffv",
 332                                 FT_UINT16,
 333                                 BASE_DEC,
 334                                 NULL,
 335                                 0x0,
 336                                 NULL, HFILL
 337                         }
 338                 },
 339
 340                 {
 341                         &hf_rtp_mpg_ffc,
 342                         {
 343                                 "FFC",
 344                                 "rtp.payload_mpeg_ffc",
 345                                 FT_UINT16,
 346                                 BASE_DEC,
 347                                 NULL,
 348                                 0x0,
 349                                 NULL, HFILL
 350                         }
 351                 },
 352                 {
 353                         &hf_rtp_mpg_data,
 354                         {
 355                                 "MPEG-1 stream",
 356                                 "mpeg1.stream",
 357                                 FT_BYTES,
 358                                 BASE_NONE,
 359                                 NULL,
 360                                 0x0,
 361                                 NULL, HFILL
 362                         }
 363                 },
 364
 365         };
 366
 367         static gint *ett[] =
 368         {
 369                 &ett_mpg,
 370         };
 371
 372
 373         proto_mpg = proto_register_protocol("RFC 2250 MPEG1","MPEG1","mpeg1");
 374         proto_register_field_array(proto_mpg, hf, array_length(hf));
 375         proto_register_subtree_array(ett, array_length(ett));
 376 }
 377
 378 void
 379 proto_reg_handoff_mpeg1(void)
 380 {
 381         dissector_handle_t mpeg1_handle;
 382
 383         mpeg1_handle = create_dissector_handle(dissect_mpeg1, proto_mpg);
 384         dissector_add_uint("rtp.pt", PT_MPV, mpeg1_handle);
 385 }