epan/dissectors/packet-h263.c

   1 /* packet-h263.c
   2  *
   3  * Routines for ITU-T Recommendation H.263 dissection
   4  *
   5  * Copyright 2003 Niklas Ögren <niklas.ogren@7l.se>
   6  * Seven Levels Consultants AB
   7  *
   8  * $Id$
   9  *
  10  * Wireshark - Network traffic analyzer
  11  * By Gerald Combs <gerald@wireshark.org>
  12  * Copyright 1998 Gerald Combs
  13  *
  14  * Copied structure from packet-h261.c
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License
  18  * as published by the Free Software Foundation; either version 2
  19  * of the License, or (at your option) any later version.
  20  *
  21  * This program is distributed in the hope that it will be useful,
  22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  * GNU General Public License for more details.
  25  *
  26  * You should have received a copy of the GNU General Public License
  27  * along with this program; if not, write to the Free Software
  28  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  29  */
  30
  31 /*
  32  * This dissector tries to dissect the H.263 protocol according to
  33  * ITU-T Recommendations and RFC 2190
  34  */
  35
  36
  37 #ifdef HAVE_CONFIG_H
  38 # include "config.h"
  39 #endif
  40
  41 #include <glib.h>
  42 #include <epan/packet.h>
  43
  44 #include <stdio.h>
  45 #include <string.h>
  46
  47 #include <epan/rtp_pt.h>
  48 #include <epan/iax2_codec_type.h>
  49
  50 static void dissect_h263_data( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree );
  51
  52 /* H.263 header fields             */
  53 static int proto_h263          = -1;
  54 static int proto_h263_data     = -1;
  55
  56 /* Mode A header */
  57 static int hf_h263_ftype = -1;
  58 static int hf_h263_pbframes = -1;
  59 static int hf_h263_sbit = -1;
  60 static int hf_h263_ebit = -1;
  61 static int hf_h263_srcformat = -1;
  62 static int hf_h263_picture_coding_type = -1;
  63 static int hf_h263_unrestricted_motion_vector = -1;
  64 static int hf_h263_syntax_based_arithmetic = -1;
  65 static int hf_h263_advanced_prediction = -1;
  66 static int hf_h263_r = -1;
  67 static int hf_h263_rr = -1;
  68 static int hf_h263_dbq = -1;
  69 static int hf_h263_trb = -1;
  70 static int hf_h263_tr = -1;
  71 /* Additional fields for Mode B or C header */
  72 static int hf_h263_quant = -1;
  73 static int hf_h263_gobn = -1;
  74 static int hf_h263_mba = -1;
  75 static int hf_h263_hmv1 = -1;
  76 static int hf_h263_vmv1 = -1;
  77 static int hf_h263_hmv2 = -1;
  78 static int hf_h263_vmv2 = -1;
  79 /* Fields for the data section */
  80 static int hf_h263_psc = -1;
  81 static int hf_h263_gbsc = -1;
  82 static int hf_h263_TR =-1;
  83 static int hf_h263_split_screen_indicator = -1;
  84 static int hf_h263_document_camera_indicator = -1;
  85 static int hf_h263_full_picture_freeze_release = -1;
  86 static int hf_h263_source_format = -1;
  87 static int hf_h263_payload_picture_coding_type = -1;
  88 static int hf_h263_opt_unres_motion_vector_mode = -1;
  89 static int hf_h263_syntax_based_arithmetic_coding_mode = -1;
  90 static int hf_h263_optional_advanced_prediction_mode = -1;
  91 static int hf_h263_PB_frames_mode = -1;
  92 static int hf_h263_data        = -1;
  93 static int hf_h263_payload     = -1;
  94 static int hf_h263_GN          = -1;
  95
  96 /* Source format types */
  97 #define SRCFORMAT_FORB   0  /* forbidden */
  98 #define SRCFORMAT_SQCIF  1
  99 #define SRCFORMAT_QCIF   2
 100 #define SRCFORMAT_CIF    3
 101 #define SRCFORMAT_4CIF   4
 102 #define SRCFORMAT_16CIF  5
 103
 104 static const value_string srcformat_vals[] =
 105 {
 106   { SRCFORMAT_FORB,     "forbidden" },
 107   { SRCFORMAT_SQCIF,    "sub-QCIF 128x96" },
 108   { SRCFORMAT_QCIF,     "QCIF 176x144" },
 109   { SRCFORMAT_CIF,      "CIF 352x288" },
 110   { SRCFORMAT_4CIF,     "4CIF 704x576" },
 111   { SRCFORMAT_16CIF,    "16CIF 1408x1152" },
 112   { 0,          NULL },
 113 };
 114
 115 static const true_false_string on_off_flg = {
 116   "On",
 117   "Off"
 118 };
 119 static const true_false_string picture_coding_type_flg = {
 120   "INTER (P-picture)",
 121   "INTRA (I-picture)"
 122 };
 123
 124 static const true_false_string PB_frames_mode_flg = {
 125   "PB-frame",
 126   "Normal I- or P-picture"
 127 };
 128
 129 /* H.263 fields defining a sub tree */
 130 static gint ett_h263                    = -1;
 131 static gint ett_h263_payload    = -1;
 132 static void
 133 dissect_h263( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
 134 {
 135         proto_item *ti                                  = NULL;
 136         proto_tree *h263_tree                   = NULL;
 137         unsigned int offset                             = 0;
 138         unsigned int h263_version               = 0;
 139         tvbuff_t *next_tvb;
 140
 141         h263_version = (tvb_get_guint8( tvb, offset ) & 0xc0 ) >> 6;
 142
 143         if ( check_col( pinfo->cinfo, COL_PROTOCOL ) )   {
 144                 col_set_str( pinfo->cinfo, COL_PROTOCOL, "H.263 " );
 145         }
 146
 147         if( h263_version == 0x00) {
 148           if ( check_col( pinfo->cinfo, COL_INFO) ) {
 149             col_append_str( pinfo->cinfo, COL_INFO, "MODE A ");
 150           }
 151         }
 152         else if( h263_version == 0x02) {
 153           if ( check_col( pinfo->cinfo, COL_INFO) ) {
 154             col_append_str( pinfo->cinfo, COL_INFO, "MODE B ");
 155           }
 156         }
 157         else if( h263_version == 0x03) {
 158           if ( check_col( pinfo->cinfo, COL_INFO) ) {
 159             col_append_str( pinfo->cinfo, COL_INFO, "MODE C ");
 160           }
 161         }
 162
 163         if ( tree ) {
 164           ti = proto_tree_add_item( tree, proto_h263, tvb, offset, -1, FALSE );
 165           h263_tree = proto_item_add_subtree( ti, ett_h263 );
 166
 167           /* FBIT 1st octet, 1 bit */
 168           proto_tree_add_boolean( h263_tree, hf_h263_ftype, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x80 );
 169           /* PBIT 1st octet, 1 bit */
 170           proto_tree_add_boolean( h263_tree, hf_h263_pbframes, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x40 );
 171           /* SBIT 1st octet, 3 bits */
 172           proto_tree_add_uint( h263_tree, hf_h263_sbit, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x38 ) >> 3 );
 173           /* EBIT 1st octet, 3 bits */
 174           proto_tree_add_uint( h263_tree, hf_h263_ebit, tvb, offset, 1, tvb_get_guint8( tvb, offset )  & 0x7 );
 175
 176           offset++;
 177
 178           /* SRC 2nd octet, 3 bits */
 179           proto_tree_add_uint( h263_tree, hf_h263_srcformat, tvb, offset, 1, tvb_get_guint8( tvb, offset ) >> 5 );
 180
 181           if(h263_version == 0x00) { /* MODE A */
 182             /* I flag, 1 bit */
 183             proto_tree_add_boolean( h263_tree, hf_h263_picture_coding_type, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x10 );
 184             /* U flag, 1 bit */
 185             proto_tree_add_boolean( h263_tree, hf_h263_unrestricted_motion_vector, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x08 );
 186             /* S flag, 1 bit */
 187             proto_tree_add_boolean( h263_tree, hf_h263_syntax_based_arithmetic, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x04 );
 188             /* A flag, 1 bit */
 189             proto_tree_add_boolean( h263_tree, hf_h263_advanced_prediction, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x02 );
 190
 191             /* Reserved 2nd octect, 1 bit + 3rd octect 3 bits */
 192             proto_tree_add_uint( h263_tree, hf_h263_r, tvb, offset, 2, ( ( tvb_get_guint8( tvb, offset ) & 0x1 ) << 3 ) + ( ( tvb_get_guint8( tvb, offset + 1 ) & 0xe0 ) >> 5 ) );
 193
 194             offset++;
 195
 196             /* DBQ 3 octect, 2 bits */
 197             proto_tree_add_uint( h263_tree, hf_h263_dbq, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x18 ) >> 3 );
 198             /* TRB 3 octect, 3 bits */
 199             proto_tree_add_uint( h263_tree, hf_h263_trb, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x07 ) );
 200
 201             offset++;
 202
 203             /* TR 4 octect, 8 bits */
 204             proto_tree_add_uint( h263_tree, hf_h263_tr, tvb, offset, 1, tvb_get_guint8( tvb, offset ) );
 205
 206             offset++;
 207
 208           } else { /* MODE B or MODE C */
 209
 210             /* QUANT 2 octect, 5 bits */
 211             proto_tree_add_uint( h263_tree, hf_h263_quant, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x1f );
 212
 213             offset++;
 214
 215             /* GOBN 3 octect, 5 bits */
 216             proto_tree_add_uint( h263_tree, hf_h263_gobn, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0xf8 ) >> 3);
 217             /* MBA 3 octect, 3 bits + 4 octect 6 bits */
 218             proto_tree_add_uint( h263_tree, hf_h263_mba, tvb, offset, 2, ( ( tvb_get_guint8( tvb, offset ) & 0x7 ) << 6 ) + ( ( tvb_get_guint8( tvb, offset + 1 ) & 0xfc ) >> 2 ) );
 219
 220             offset++;
 221
 222             /* Reserved 4th octect, 2 bits */
 223             proto_tree_add_uint( h263_tree, hf_h263_r, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x3 ) );
 224
 225             offset++;
 226
 227             /* I flag, 1 bit */
 228             proto_tree_add_boolean( h263_tree, hf_h263_picture_coding_type, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x80 );
 229             /* U flag, 1 bit */
 230             proto_tree_add_boolean( h263_tree, hf_h263_unrestricted_motion_vector, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x40 );
 231             /* S flag, 1 bit */
 232             proto_tree_add_boolean( h263_tree, hf_h263_syntax_based_arithmetic, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x20 );
 233             /* A flag, 1 bit */
 234             proto_tree_add_boolean( h263_tree, hf_h263_advanced_prediction, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x10 );
 235
 236             /* HMV1 5th octect, 4 bits + 6th octect 3 bits*/
 237             proto_tree_add_uint( h263_tree, hf_h263_hmv1, tvb, offset, 2,( ( tvb_get_guint8( tvb, offset ) & 0xf ) << 3 ) + ( ( tvb_get_guint8( tvb, offset+1 ) & 0xe0 ) >> 5) );
 238
 239             offset++;
 240
 241             /* VMV1 6th octect, 5 bits + 7th octect 2 bits*/
 242             proto_tree_add_uint( h263_tree, hf_h263_vmv1, tvb, offset, 2,( ( tvb_get_guint8( tvb, offset ) & 0x1f ) << 2 ) + ( ( tvb_get_guint8( tvb, offset+1 ) & 0xc0 ) >> 6) );
 243
 244             offset++;
 245
 246             /* HMV2 7th octect, 6 bits + 8th octect 1 bit*/
 247             proto_tree_add_uint( h263_tree, hf_h263_hmv2, tvb, offset, 2,( ( tvb_get_guint8( tvb, offset ) & 0x3f ) << 1 ) + ( ( tvb_get_guint8( tvb, offset+1 ) & 0xf0 ) >> 7) );
 248
 249             offset++;
 250
 251             /* VMV2 8th octect, 7 bits*/
 252             proto_tree_add_uint( h263_tree, hf_h263_vmv2, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x7f );
 253
 254             offset++;
 255
 256             if(h263_version == 0x03) { /* MODE C */
 257               /* Reserved 9th to 11th octect, 8 + 8 + 3 bits */
 258               proto_tree_add_uint( h263_tree, hf_h263_rr, tvb, offset, 3, ( tvb_get_guint8( tvb, offset ) << 11 ) + ( tvb_get_guint8( tvb, offset + 1 ) << 3 ) + ( ( tvb_get_guint8( tvb, offset + 2 ) & 0xe0 ) >> 5 ) );
 259
 260               offset+=2;
 261
 262               /* DBQ 11th octect, 2 bits */
 263               proto_tree_add_uint( h263_tree, hf_h263_dbq, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x18 ) >>3 );
 264               /* TRB 11th octect, 3 bits */
 265               proto_tree_add_uint( h263_tree, hf_h263_trb, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x07 );
 266
 267               offset++;
 268
 269               /* TR 12th octect, 8 bits */
 270               proto_tree_add_uint( h263_tree, hf_h263_tr, tvb, offset, 1, tvb_get_guint8( tvb, offset ) );
 271
 272               offset++;
 273             } /* end mode c */
 274           } /* end not mode a */
 275
 276           /* The rest of the packet is the H.263 stream */
 277           next_tvb = tvb_new_subset( tvb, offset, tvb_length(tvb) - offset, tvb_reported_length(tvb) - offset);
 278           dissect_h263_data( next_tvb, pinfo, h263_tree );
 279
 280         }
 281 }
 282
 283
 284 static void dissect_h263_data( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
 285 {
 286         guint offset = 0;
 287         proto_item *h263_payload_item   = NULL;
 288         proto_tree *h263_payload_tree   = NULL;
 289         guint32 data;
 290         guint8 octet;
 291
 292         if ( check_col( pinfo->cinfo, COL_INFO) ) {
 293           col_append_str( pinfo->cinfo, COL_INFO, "H263 payload ");
 294         }
 295
 296         if( tree ) {
 297           h263_payload_item = proto_tree_add_item( tree, hf_h263_payload, tvb, offset, -1, FALSE );
 298           h263_payload_tree = proto_item_add_subtree( h263_payload_item, ett_h263_payload );
 299         }
 300
 301         /* Check for PSC, PSC is a word of 22 bits. Its value is 0000 0000 0000 0000' 1000 00xx xxxx xxxx. */
 302         data = tvb_get_ntohl(tvb, offset);
 303
 304         if (( data & 0xffff8000) == 0x00008000 ) { /* PSC or Group of Block Start Code (GBSC) found */
 305                 if (( data & 0x00007c00) == 0 ) { /* PSC found */
 306                         if ( check_col( pinfo->cinfo, COL_INFO) )
 307                           col_append_str( pinfo->cinfo, COL_INFO, "(PSC) ");
 308                         if( tree ) {
 309                           proto_tree_add_uint(h263_payload_tree, hf_h263_psc,tvb, offset,3,data);
 310                           offset = offset + 2;
 311                           proto_tree_add_uint(h263_payload_tree, hf_h263_TR,tvb, offset,2,data);
 312                           /* Last two bits in the 32 bits fetched
 313                            * Bit 1: Always "1", in order to avoid start code emulation.
 314                            * Bit 2: Always "0", for distinction with Recommendation H.261.
 315                            */
 316                           offset = offset + 2;
 317                           /* Bit 3: Split screen indicator, "0" off, "1" on. */
 318                           proto_tree_add_item( h263_payload_tree, hf_h263_split_screen_indicator, tvb, offset, 1, FALSE );
 319                           /* Bit 4: Document camera indicator, */
 320                           proto_tree_add_item( h263_payload_tree, hf_h263_document_camera_indicator, tvb, offset, 1, FALSE );
 321                           /* Bit 5: Full Picture Freeze Release, "0" off, "1" on. */
 322                           proto_tree_add_item( h263_payload_tree, hf_h263_full_picture_freeze_release, tvb, offset, 1, FALSE );
 323                           /* Bits 6-8: Source Format, "000" forbidden, "001" sub-QCIF, "010" QCIF, "011" CIF,
 324                            * "100" 4CIF, "101" 16CIF, "110" reserved, "111" extended PTYPE.
 325                            */
 326                           proto_tree_add_item( h263_payload_tree, hf_h263_source_format, tvb, offset, 1, TRUE );
 327                           octet = tvb_get_guint8(tvb,offset);
 328                           if (( octet & 0x1c) != 0x1c){
 329                                   /* Not extended PTYPE */
 330                                   /* Bit 9: Picture Coding Type, "0" INTRA (I-picture), "1" INTER (P-picture). */
 331                                   proto_tree_add_item( h263_payload_tree, hf_h263_payload_picture_coding_type, tvb, offset, 1, FALSE );
 332                                   /* Bit 10: Optional Unrestricted Motion Vector mode (see Annex D), "0" off, "1" on. */
 333                                   proto_tree_add_item( h263_payload_tree, hf_h263_opt_unres_motion_vector_mode, tvb, offset, 1, FALSE );
 334                                   offset++;
 335                                   /* Bit 11: Optional Syntax-based Arithmetic Coding mode (see Annex E), "0" off, "1" on.*/
 336                                   proto_tree_add_item( h263_payload_tree, hf_h263_syntax_based_arithmetic_coding_mode, tvb, offset, 1, FALSE );
 337                                   /* Bit 12: Optional Advanced Prediction mode (see Annex F), "0" off, "1" on.*/
 338                                   proto_tree_add_item( h263_payload_tree, hf_h263_optional_advanced_prediction_mode, tvb, offset, 1, FALSE );
 339                                   /* Bit 13: Optional PB-frames mode (see Annex G), "0" normal I- or P-picture, "1" PB-frame.*/
 340                                   proto_tree_add_item( h263_payload_tree, hf_h263_PB_frames_mode, tvb, offset, 1, FALSE );
 341                           }
 342                         }
 343                 } else { /* GBSC found */
 344                         if ( check_col( pinfo->cinfo, COL_INFO) )
 345                           col_append_str( pinfo->cinfo, COL_INFO, "(GBSC) ");
 346                         if( tree ) {
 347                                 /* Group of Block Start Code (GBSC) (17 bits)
 348                                  * A word of 17 bits. Its value is 0000 0000 0000 0000 1. GOB start codes may be byte aligned. This
 349                                  * can be achieved by inserting GSTUF before the start code such that the first bit of the start code is
 350                                  * the first (most significant) bit of a byte.
 351                                  *
 352                                  */
 353                                 proto_tree_add_uint(h263_payload_tree, hf_h263_gbsc,tvb, offset,3,data);
 354                                 proto_tree_add_uint(h263_payload_tree, hf_h263_GN, tvb, offset,3,data);
 355                                 /* GN is followed by (optionally) GBSI, then
 356                                  * GFID and GQUANT, but decoding them requires
 357                                  * knowing the value of CPM in the picture
 358                                  * header */
 359                                 offset = offset + 2;
 360                         }
 361                 }
 362         }
 363         if( tree )
 364                 proto_tree_add_item( h263_payload_tree, hf_h263_data, tvb, offset, -1, FALSE );
 365 }
 366
 367 void
 368 proto_register_h263(void)
 369 {
 370         static hf_register_info hf[] =
 371         {
 372                 {
 373                         &hf_h263_ftype,
 374                         {
 375                                 "F",
 376                                 "h263.ftype",
 377                                 FT_BOOLEAN,
 378                                 BASE_NONE,
 379                                 NULL,
 380                                 0x0,
 381                                 "Indicates the mode of the payload header (MODE A or B/C)", HFILL
 382                         }
 383                 },
 384                 {
 385                         &hf_h263_pbframes,
 386                         {
 387                                 "p/b frame",
 388                                 "h263.pbframes",
 389                                 FT_BOOLEAN,
 390                                 BASE_NONE,
 391                                 NULL,
 392                                 0x0,
 393                                 "Optional PB-frames mode as defined by H.263 (MODE C)", HFILL
 394                         }
 395                 },
 396                 {
 397                         &hf_h263_sbit,
 398                         {
 399                                 "Start bit position",
 400                                 "h263.sbit",
 401                                 FT_UINT8,
 402                                 BASE_DEC,
 403                                 NULL,
 404                                 0x0,
 405                                 "Start bit position specifies number of most significant bits that shall be ignored in the first data byte.", HFILL
 406                         }
 407                 },
 408                 {
 409                         &hf_h263_ebit,
 410                         {
 411                                 "End bit position",
 412                                 "h263.ebit",
 413                                 FT_UINT8,
 414                                 BASE_DEC,
 415                                 NULL,
 416                                 0x0,
 417                                 "End bit position specifies number of least significant bits that shall be ignored in the last data byte.", HFILL
 418                         }
 419                 },
 420                 {
 421                         &hf_h263_srcformat,
 422                         {
 423                                 "SRC format",
 424                                 "h263.srcformat",
 425                                 FT_UINT8,
 426                                 BASE_DEC,
 427                                 VALS(srcformat_vals),
 428                                 0x0,
 429                                 "Source format specifies the resolution of the current picture.", HFILL
 430                         }
 431                 },
 432                 {
 433                         &hf_h263_picture_coding_type,
 434                         {
 435                                 "Inter-coded frame",
 436                                 "h263.picture_coding_type",
 437                                 FT_BOOLEAN,
 438                                 BASE_NONE,
 439                                 NULL,
 440                                 0x0,
 441                                 "Picture coding type, intra-coded (false) or inter-coded (true)", HFILL
 442                         }
 443                 },
 444                 {
 445                         &hf_h263_unrestricted_motion_vector,
 446                         {
 447                                 "Motion vector",
 448                                 "h263.unrestricted_motion_vector",
 449                                 FT_BOOLEAN,
 450                                 BASE_NONE,
 451                                 NULL,
 452                                 0x0,
 453                                 "Unrestricted Motion Vector option for current picture", HFILL
 454                         }
 455                 },
 456                 {
 457                         &hf_h263_syntax_based_arithmetic,
 458                         {
 459                                 "Syntax-based arithmetic coding",
 460                                 "h263.syntax_based_arithmetic",
 461                                 FT_BOOLEAN,
 462                                 BASE_NONE,
 463                                 NULL,
 464                                 0x0,
 465                                 "Syntax-based Arithmetic Coding option for current picture", HFILL
 466                         }
 467                 },
 468                 {
 469                         &hf_h263_advanced_prediction,
 470                         {
 471                                 "Advanced prediction option",
 472                                 "h263.advanced_prediction",
 473                                 FT_BOOLEAN,
 474                                 BASE_NONE,
 475                                 NULL,
 476                                 0x0,
 477                                 "Advanced Prediction option for current picture", HFILL
 478                         }
 479                 },
 480                 {
 481                         &hf_h263_dbq,
 482                         {
 483                                 "Differential quantization parameter",
 484                                 "h263.dbq",
 485                                 FT_UINT8,
 486                                 BASE_DEC,
 487                                 NULL,
 488                                 0x0,
 489                                 "Differential quantization parameter used to calculate quantizer for the B frame based on quantizer for the P frame, when PB-frames option is used.", HFILL
 490                         }
 491                 },
 492                 {
 493                         &hf_h263_trb,
 494                         {
 495                                 "Temporal Reference for B frames",
 496                                 "h263.trb",
 497                                 FT_UINT8,
 498                                 BASE_DEC,
 499                                 NULL,
 500                                 0x0,
 501                                 "Temporal Reference for the B frame as defined by H.263", HFILL
 502                         }
 503                 },
 504                 {
 505                         &hf_h263_tr,
 506                         {
 507                                 "Temporal Reference for P frames",
 508                                 "h263.tr",
 509                                 FT_UINT8,
 510                                 BASE_DEC,
 511                                 NULL,
 512                                 0x0,
 513                                 "Temporal Reference for the P frame as defined by H.263", HFILL
 514                         }
 515                 },
 516                 {
 517                         &hf_h263_quant,
 518                         {
 519                                 "Quantizer",
 520                                 "h263.quant",
 521                                 FT_UINT8,
 522                                 BASE_DEC,
 523                                 NULL,
 524                                 0x0,
 525                                 "Quantization value for the first MB coded at the starting of the packet.", HFILL
 526                         }
 527                 },
 528                 {
 529                         &hf_h263_gobn,
 530                         {
 531                                 "GOB Number",
 532                                 "h263.gobn",
 533                                 FT_UINT8,
 534                                 BASE_DEC,
 535                                 NULL,
 536                                 0x0,
 537                                 "GOB number in effect at the start of the packet.", HFILL
 538                         }
 539                 },
 540                 {
 541                         &hf_h263_mba,
 542                         {
 543                                 "Macroblock address",
 544                                 "h263.mba",
 545                                 FT_UINT16,
 546                                 BASE_DEC,
 547                                 NULL,
 548                                 0x0,
 549                                 "The address within the GOB of the first MB in the packet, counting from zero in scan order.", HFILL
 550                         }
 551                 },
 552                 {
 553                         &hf_h263_hmv1,
 554                         {
 555                                 "Horizontal motion vector 1",
 556                                 "h263.hmv1",
 557                                 FT_UINT8,
 558                                 BASE_DEC,
 559                                 NULL,
 560                                 0x0,
 561                                 "Horizontal motion vector predictor for the first MB in this packet ", HFILL
 562                         }
 563                 },
 564                 {
 565                         &hf_h263_vmv1,
 566                         {
 567                                 "Vertical motion vector 1",
 568                                 "h263.vmv1",
 569                                 FT_UINT8,
 570                                 BASE_DEC,
 571                                 NULL,
 572                                 0x0,
 573                                 "Vertical motion vector predictor for the first MB in this packet ", HFILL
 574                         }
 575                 },
 576                 {
 577                         &hf_h263_hmv2,
 578                         {
 579                                 "Horizontal motion vector 2",
 580                                 "h263.hmv2",
 581                                 FT_UINT8,
 582                                 BASE_DEC,
 583                                 NULL,
 584                                 0x0,
 585                                 "Horizontal motion vector predictor for block number 3 in the first MB in this packet when four motion vectors are used with the advanced prediction option.", HFILL
 586                         }
 587                 },
 588                 {
 589                         &hf_h263_vmv2,
 590                         {
 591                                 "Vertical motion vector 2",
 592                                 "h263.vmv2",
 593                                 FT_UINT8,
 594                                 BASE_DEC,
 595                                 NULL,
 596                                 0x0,
 597                                 "Vertical motion vector predictor for block number 3 in the first MB in this packet when four motion vectors are used with the advanced prediction option.", HFILL
 598                         }
 599                 },
 600                 {
 601                         &hf_h263_r,
 602                         {
 603                                 "Reserved field",
 604                                 "h263.r",
 605                                 FT_UINT8,
 606                                 BASE_DEC,
 607                                 NULL,
 608                                 0x0,
 609                                 "Reserved field that houls contain zeroes", HFILL
 610                         }
 611                 },
 612                 {
 613                         &hf_h263_rr,
 614                         {
 615                                 "Reserved field 2",
 616                                 "h263.rr",
 617                                 FT_UINT16,
 618                                 BASE_DEC,
 619                                 NULL,
 620                                 0x0,
 621                                 "Reserved field that should contain zeroes", HFILL
 622                         }
 623                 },
 624                 {
 625                         &hf_h263_payload,
 626                         {
 627                                 "H.263 payload",
 628                                 "h263.payload",
 629                                 FT_NONE,
 630                                 BASE_NONE,
 631                                 NULL,
 632                                 0x0,
 633                                 "The actual H.263 data", HFILL
 634                         }
 635                 },
 636                 {
 637                         &hf_h263_data,
 638                         {
 639                                 "H.263 stream",
 640                                 "h263.stream",
 641                                 FT_BYTES,
 642                                 BASE_NONE,
 643                                 NULL,
 644                                 0x0,
 645                                 "The H.263 stream including its Picture, GOB or Macro block start code.", HFILL
 646                         }
 647                 },
 648                 {
 649                         &hf_h263_psc,
 650                         {
 651                                 "H.263 Picture start Code",
 652                                 "h263.psc",
 653                                 FT_UINT32,
 654                                 BASE_HEX,
 655                                 NULL,
 656                                 0xfffffc00,
 657                                 "Picture start Code, PSC", HFILL
 658                         }
 659                 },
 660                 { &hf_h263_gbsc,
 661                         {
 662                                 "H.263 Group of Block Start Code",
 663                                 "h263.gbsc",
 664                                 FT_UINT32,
 665                                 BASE_HEX,
 666                                 NULL,
 667                                 0xffff8000,
 668                                 "Group of Block Start Code", HFILL
 669                         }
 670                 },
 671                 {
 672                         &hf_h263_TR,
 673                         {
 674                                 "H.263 Temporal Reference",
 675                                 "h263.tr2",
 676                                 FT_UINT32,
 677                                 BASE_HEX,
 678                                 NULL,
 679                                 0x000003fc,
 680                                 "Temporal Reference, TR", HFILL
 681                         }
 682                 },
 683                 {
 684                         &hf_h263_split_screen_indicator,
 685                         {
 686                                 "H.263 Split screen indicator",
 687                                 "h263.split_screen_indicator",
 688                                 FT_BOOLEAN,
 689                                 8,
 690                                 TFS(&on_off_flg),
 691                                 0x80,
 692                                 "Split screen indicator", HFILL
 693                         }
 694                 },
 695                 {
 696                         &hf_h263_document_camera_indicator,
 697                         {
 698                                 "H.263 Document camera indicator",
 699                                 "h263.document_camera_indicator",
 700                                 FT_BOOLEAN,
 701                                 8,
 702                                 TFS(&on_off_flg),
 703                                 0x40,
 704                                 "Document camera indicator", HFILL
 705                         }
 706                 },
 707                 {
 708                         &hf_h263_full_picture_freeze_release,
 709                         {
 710                                 "H.263 Full Picture Freeze Release",
 711                                 "h263.split_screen_indicator",
 712                                 FT_BOOLEAN,
 713                                 8,
 714                                 TFS(&on_off_flg),
 715                                 0x20,
 716                                 "Full Picture Freeze Release", HFILL
 717                         }
 718                 },
 719                 {
 720                         &hf_h263_source_format,
 721                         {
 722                                 "H.263 Source Format",
 723                                 "h263.split_screen_indicator",
 724                                 FT_UINT8,
 725                                 BASE_HEX,
 726                                 VALS(srcformat_vals),
 727                                 0x1c,
 728                                 "Source Format", HFILL
 729                         }
 730                 },
 731                 {
 732                         &hf_h263_payload_picture_coding_type,
 733                         {
 734                                 "H.263 Picture Coding Type",
 735                                 "h263.picture_coding_type",
 736                                 FT_BOOLEAN,
 737                                 8,
 738                                 TFS(&picture_coding_type_flg),
 739                                 0x02,
 740                                 "Picture Coding Typet", HFILL
 741                         }
 742                 },
 743                 {
 744                         &hf_h263_opt_unres_motion_vector_mode,
 745                         {
 746                                 "H.263 Optional Unrestricted Motion Vector mode",
 747                                 "h263.opt_unres_motion_vector_mode",
 748                                 FT_BOOLEAN,
 749                                 8,
 750                                 TFS(&on_off_flg),
 751                                 0x01,
 752                                 "Optional Unrestricted Motion Vector mode", HFILL
 753                         }
 754                 },
 755                 {
 756                         &hf_h263_syntax_based_arithmetic_coding_mode,
 757                         {
 758                                 "H.263 Optional Syntax-based Arithmetic Coding mode",
 759                                 "h263.syntax_based_arithmetic_coding_mode",
 760                                 FT_BOOLEAN,
 761                                 8,
 762                                 TFS(&on_off_flg),
 763                                 0x80,
 764                                 "Optional Syntax-based Arithmetic Coding mode", HFILL
 765                         }
 766                 },
 767                 {
 768                         &hf_h263_optional_advanced_prediction_mode,
 769                         {
 770                                 "H.263 Optional Advanced Prediction mode",
 771                                 "h263.optional_advanced_prediction_mode",
 772                                 FT_BOOLEAN,
 773                                 8,
 774                                 TFS(&on_off_flg),
 775                                 0x40,
 776                                 "Optional Advanced Prediction mode", HFILL
 777                         }
 778                 },
 779                 {
 780                         &hf_h263_PB_frames_mode,
 781                         {
 782                                 "H.263 Optional PB-frames mode",
 783                                 "h263.PB_frames_mode",
 784                                 FT_BOOLEAN,
 785                                 8,
 786                                 TFS(&PB_frames_mode_flg),
 787                                 0x20,
 788                                 "Optional PB-frames mode", HFILL
 789                         }
 790                 },
 791                 {
 792                         &hf_h263_GN,
 793                         {
 794                                 "H.263 Group Number",
 795                                 "h263.gn",
 796                                 FT_UINT32,
 797                                 BASE_DEC,
 798                                 NULL,
 799                                 0x00007c00,
 800                                 "Group Number, GN", HFILL
 801                         }
 802                 },
 803 };
 804
 805         static gint *ett[] =
 806         {
 807                 &ett_h263,
 808                 &ett_h263_payload,
 809         };
 810
 811
 812         proto_h263 = proto_register_protocol("ITU-T Recommendation H.263 RTP Payload header (RFC2190)",
 813             "H.263", "h263");
 814         proto_h263_data = proto_register_protocol("ITU-T Recommendation H.263",
 815             "H.263 data", "h263data");
 816         proto_register_field_array(proto_h263, hf, array_length(hf));
 817         proto_register_subtree_array(ett, array_length(ett));
 818         register_dissector("h263", dissect_h263, proto_h263);
 819         register_dissector("h263data", dissect_h263_data, proto_h263_data);
 820 }
 821
 822 void
 823 proto_reg_handoff_h263(void)
 824 {
 825         dissector_handle_t h263_handle;
 826
 827         h263_handle = find_dissector("h263");
 828         dissector_add("rtp.pt", PT_H263, h263_handle);
 829         dissector_add("iax2.codec", AST_FORMAT_H263, h263_handle);
 830 }