packet-mpeg1.c

   1 /* packet-mpeg1.c
   2  *
   3  * Routines for RFC 2250 MPEG-1 dissection
   4  *
   5  * $Id: packet-mpeg1.c,v 1.6 2002/01/24 09:20:49 guy Exp $
   6  *
   7  * Copyright 2001,
   8  * Francisco Javier Cabello Torres, <fjcabello@vtools.es>
   9  *
  10  * Ethereal - Network traffic analyzer
  11  * By Gerald Combs <gerald@ethereal.com>
  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  * This dissector is called by the RTP dissector
  33  */
  34
  35
  36 #ifdef HAVE_CONFIG_H
  37 # include "config.h"
  38 #endif
  39
  40 #include <glib.h>
  41 #include <epan/packet.h>
  42
  43 #ifdef HAVE_SYS_TYPES_H
  44 #  include <sys/types.h>
  45 #endif
  46
  47 #ifdef HAVE_NETINET_IN_H
  48 #  include <netinet/in.h>
  49 #endif
  50
  51 #include <stdio.h>
  52 #include <string.h>
  53
  54 #define RTP_MPG_MBZ(word) ( word >> 11)
  55 #define RTP_MPG_T(word)   ( (word >> 10) & 1 )
  56 #define RTP_MPG_TR(word)   ( word & 0x3ff )
  57
  58 #define RTP_MPG_AN(octet) ( octet >> 7)
  59 #define RTP_MPG_N(octet)  ( (octet >> 6) & 1 )
  60 #define RTP_MPG_S(octet)  ( (octet >> 5) & 1 )
  61 #define RTP_MPG_B(octet)  ( (octet >> 4) & 1 )
  62 #define RTP_MPG_E(octet)  ( (octet >> 3) & 1 )
  63 #define RTP_MPG_P(octet)  ( octet & 7 )
  64
  65 #define RTP_MPG_FBV(octet) ( (octet >> 7) & 1 )
  66 #define RTP_MPG_BFC(octet) ( (octet >> 4) & 7 )
  67 #define RTP_MPG_FFV(octet) ( (octet >> 3) & 1 )
  68 #define RTP_MPG_FFC(octet) (  octet & 7 )
  69
  70
  71 /* MPEG1 header fields             */
  72
  73
  74 static int proto_mpg          = -1;
  75
  76 static int hf_rtp_mpg_mbz     = -1;
  77 static int hf_rtp_mpg_T       = -1;
  78 static int hf_rtp_mpg_tr      = -1;
  79 static int hf_rtp_mpg_an      = -1;
  80 static int hf_rtp_mpg_n       = -1;
  81 static int hf_rtp_mpg_s       = -1;
  82 static int hf_rtp_mpg_b       = -1;
  83 static int hf_rtp_mpg_e       = -1;
  84 static int hf_rtp_mpg_p       = -1;
  85
  86
  87 static int hf_rtp_mpg_fbv     = -1;
  88 static int hf_rtp_mpg_bfc     = -1;
  89 static int hf_rtp_mpg_ffv     = -1;
  90 static int hf_rtp_mpg_ffc     = -1;
  91 static int hf_rtp_mpg_data    = -1;
  92
  93
  94
  95 /* MPEG-1 fields defining a sub tree */
  96 static gint ett_mpg           = -1;
  97
  98 static const value_string rtp_mpg_picture_types_vals[] =
  99 {
 100         { 0, "Forbidden" },
 101         { 1, "I-Picture" },
 102         { 2, "P-Picture" },
 103         { 3, "B-Picture" },
 104         { 4, "D-Picture" },
 105         { 5, "reserved" },
 106         { 6, "reserved" },
 107         { 7, "reserved" },
 108         { 0, NULL },
 109 };
 110
 111 static void
 112 dissect_mpeg1( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
 113 {
 114         proto_item *ti            = NULL;
 115         proto_tree *mpg_tree     = NULL;
 116         unsigned int offset       = 0;
 117
 118         guint8      octet;
 119         guint16     word;
 120
 121
 122         guint16     mpg_mbz;
 123         guint16     mpg_T;
 124         guint16     mpg_tr;
 125         guint16     mpg_an;
 126         guint16     mpg_n;
 127         gboolean    mpg_s;
 128         gboolean    mpg_b;
 129         gboolean    mpg_e;
 130         guint16     mpg_p;
 131         guint16     mpg_fbv;
 132         guint16     mpg_bfc;
 133         guint16     mpg_ffv;
 134         guint16     mpg_ffc;
 135
 136         if ( check_col( pinfo->cinfo, COL_PROTOCOL ) )
 137           {
 138             col_set_str( pinfo->cinfo, COL_PROTOCOL, "MPEG-1" );
 139           }
 140
 141         if ( check_col( pinfo->cinfo, COL_INFO) )
 142           {
 143             col_set_str( pinfo->cinfo, COL_INFO, "MPEG-1 message");
 144           }
 145
 146         /* Get MPEG-1  fields */
 147
 148         word  =   tvb_get_guint8( tvb, offset  );
 149         word  = (word << 8) | tvb_get_guint8( tvb, offset +1 );
 150         mpg_mbz = RTP_MPG_MBZ(word);
 151         mpg_T   = RTP_MPG_T(word);
 152         mpg_tr  = RTP_MPG_TR(word);
 153
 154         octet = tvb_get_guint8( tvb, offset + 2 );
 155         mpg_an  = RTP_MPG_AN(octet);
 156         mpg_n   = RTP_MPG_N(octet);
 157         mpg_s   = RTP_MPG_S(octet);
 158         mpg_b   = RTP_MPG_B(octet);
 159         mpg_e   = RTP_MPG_E(octet);
 160         mpg_p   = RTP_MPG_P(octet);
 161
 162         octet = tvb_get_guint8( tvb, offset + 3 );
 163
 164         mpg_fbv   = RTP_MPG_FBV(octet);
 165         mpg_bfc   = RTP_MPG_BFC(octet);
 166         mpg_ffv   = RTP_MPG_FFV(octet);
 167         mpg_ffc   = RTP_MPG_FFC(octet);
 168
 169
 170         if ( tree )
 171           {
 172             ti = proto_tree_add_item( tree, proto_mpg, tvb, offset, -1, FALSE );
 173             mpg_tree = proto_item_add_subtree( ti, ett_mpg );
 174
 175             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_mbz, tvb, offset, 1, mpg_mbz );
 176             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_T  , tvb, offset, 1, mpg_T );
 177             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_tr , tvb, offset, 2, mpg_tr );
 178             offset += 2;
 179             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_an, tvb, offset, 1, mpg_an );
 180             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_n , tvb, offset, 1, mpg_n );
 181             proto_tree_add_boolean( mpg_tree, hf_rtp_mpg_s , tvb, offset, 1, mpg_s );
 182             proto_tree_add_boolean( mpg_tree, hf_rtp_mpg_b , tvb, offset, 1, mpg_b );
 183             proto_tree_add_boolean( mpg_tree, hf_rtp_mpg_e , tvb, offset, 1, mpg_e );
 184
 185             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_p, tvb , offset, 1, mpg_p );
 186             offset += 1;
 187
 188             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_fbv, tvb, offset, 1, mpg_fbv );
 189             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_bfc, tvb, offset, 1, mpg_bfc );
 190             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_ffv, tvb, offset, 1, mpg_ffv );
 191             proto_tree_add_uint( mpg_tree, hf_rtp_mpg_ffc, tvb, offset, 1, mpg_ffc );
 192             offset += 1;
 193
 194             /* The rest of the packet is the MPEG-1 stream */
 195             proto_tree_add_item( mpg_tree, hf_rtp_mpg_data, tvb, offset, tvb_length_remaining( tvb, offset ), FALSE );
 196
 197           }
 198 }
 199
 200 void
 201 proto_register_mpeg1(void)
 202 {
 203         static hf_register_info hf[] =
 204         {
 205                 {
 206                         &hf_rtp_mpg_mbz,
 207                         {
 208                                 "MBZ",
 209                                 "rtp.payload_mpeg_mbz",
 210                                 FT_UINT16,
 211                                 BASE_DEC,
 212                                 NULL,
 213                                 0x0,
 214                                 "", HFILL
 215                         }
 216                 },
 217                 {
 218                         &hf_rtp_mpg_T,
 219                         {
 220                                 "T",
 221                                 "rtp.payload_mpeg_T",
 222                                 FT_UINT16,
 223                                 BASE_DEC,
 224                                 NULL,
 225                                 0x0,
 226                                 "", HFILL
 227                         }
 228                 },
 229                 {
 230                         &hf_rtp_mpg_tr,
 231                         {
 232                                 "Temporal Reference",
 233                                 "rtp.payload_mpeg_tr",
 234                                 FT_UINT16,
 235                                 BASE_DEC,
 236                                 NULL,
 237                                 0x0,
 238                                 "", HFILL
 239                         }
 240                 },
 241                 {
 242                         &hf_rtp_mpg_an,
 243                         {
 244                                 "AN",
 245                                 "rtp.payload_mpeg_an",
 246                                 FT_UINT16,
 247                                 BASE_DEC,
 248                                 NULL,
 249                                 0x0,
 250                                 "", HFILL
 251                         }
 252                 },
 253
 254                 {
 255                         &hf_rtp_mpg_n,
 256                         {
 257                                 "New Picture Header",
 258                                 "rtp.payload_mpeg_n",
 259                                 FT_UINT16,
 260                                 BASE_DEC,
 261                                 NULL,
 262                                 0x0,
 263                                 "", HFILL
 264                         }
 265                 },
 266
 267                 {
 268                         &hf_rtp_mpg_s,
 269                         {
 270                                 "Sequence Header",
 271                                 "rtp.payload_mpeg_s",
 272                                 FT_BOOLEAN,
 273                                 BASE_DEC,
 274                                 NULL,
 275                                 0x0,
 276                                 "", HFILL
 277                         }
 278                 },
 279
 280                 {
 281                         &hf_rtp_mpg_b,
 282                         {
 283                                 "Beginning-of-slice",
 284                                 "rtp.payload_mpeg_b",
 285                                 FT_BOOLEAN,
 286                                 BASE_DEC,
 287                                 NULL,
 288                                 0x0,
 289                                 "", HFILL
 290                         }
 291                 },
 292
 293                 {
 294                         &hf_rtp_mpg_e,
 295                         {
 296                                 "End-of-slice",
 297                                 "rtp.payload_mpeg_an",
 298                                 FT_BOOLEAN,
 299                                 BASE_DEC,
 300                                 NULL,
 301                                 0x0,
 302                                 "", HFILL
 303                         }
 304                 },
 305
 306                 {
 307                         &hf_rtp_mpg_p,
 308                         {
 309                                 "Picture type",
 310                                 "rtp.payload_mpeg_p",
 311                                 FT_UINT16,
 312                                 BASE_DEC,
 313                                 VALS(rtp_mpg_picture_types_vals),
 314                                 0x0,
 315                                 "", HFILL
 316                         }
 317                 },
 318
 319                 {
 320                         &hf_rtp_mpg_fbv,
 321                         {
 322                                 "FBV",
 323                                 "rtp.payload_mpeg_fbv",
 324                                 FT_UINT16,
 325                                 BASE_DEC,
 326                                 NULL,
 327                                 0x0,
 328                                 "", HFILL
 329                         }
 330                 },
 331
 332                 {
 333                         &hf_rtp_mpg_bfc,
 334                         {
 335                                 "BFC",
 336                                 "rtp.payload_mpeg_bfc",
 337                                 FT_UINT16,
 338                                 BASE_DEC,
 339                                 NULL,
 340                                 0x0,
 341                                 "", HFILL
 342                         }
 343                 },
 344                 {
 345                         &hf_rtp_mpg_ffv,
 346                         {
 347                                 "FFV",
 348                                 "rtp.payload_mpeg_ffv",
 349                                 FT_UINT16,
 350                                 BASE_DEC,
 351                                 NULL,
 352                                 0x0,
 353                                 "", HFILL
 354                         }
 355                 },
 356
 357                 {
 358                         &hf_rtp_mpg_ffc,
 359                         {
 360                                 "FFC",
 361                                 "rtp.payload_mpeg_ffc",
 362                                 FT_UINT16,
 363                                 BASE_DEC,
 364                                 NULL,
 365                                 0x0,
 366                                 "", HFILL
 367                         }
 368                 },
 369                 {
 370                         &hf_rtp_mpg_data,
 371                         {
 372                                 "MPEG-1 stream",
 373                                 "mpeg1.stream",
 374                                 FT_BYTES,
 375                                 BASE_NONE,
 376                                 NULL,
 377                                 0x0,
 378                                 "", HFILL
 379                         }
 380                 },
 381
 382         };
 383
 384         static gint *ett[] =
 385         {
 386                 &ett_mpg,
 387         };
 388
 389
 390         proto_mpg = proto_register_protocol("RFC 2250 MPEG1","MPEG1","mpeg1");
 391         proto_register_field_array(proto_mpg, hf, array_length(hf));
 392         proto_register_subtree_array(ett, array_length(ett));
 393
 394         register_dissector("mpeg1", dissect_mpeg1, proto_mpg);
 395 }