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: packet-h263.c,v 1.4 2003/08/25 21:48:44 guy Exp $
   9  *
  10  * Ethereal - Network traffic analyzer
  11  * By Gerald Combs <gerald@ethereal.com>
  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 "rtp_pt.h"
  48
  49 /* H.263 header fields             */
  50 static int proto_h263          = -1;
  51
  52 /* Mode A header */
  53 static int hf_h263_ftype = -1;
  54 static int hf_h263_pbframes = -1;
  55 static int hf_h263_sbit = -1;
  56 static int hf_h263_ebit = -1;
  57 static int hf_h263_srcformat = -1;
  58 static int hf_h263_picture_coding_type = -1;
  59 static int hf_h263_unrestricted_motion_vector = -1;
  60 static int hf_h263_syntax_based_arithmetic = -1;
  61 static int hf_h263_advanced_prediction = -1;
  62 static int hf_h263_r = -1;
  63 static int hf_h263_rr = -1;
  64 static int hf_h263_dbq = -1;
  65 static int hf_h263_trb = -1;
  66 static int hf_h263_tr = -1;
  67 /* Additional fields for Mode B or C header */
  68 static int hf_h263_quant = -1;
  69 static int hf_h263_gobn = -1;
  70 static int hf_h263_mba = -1;
  71 static int hf_h263_hmv1 = -1;
  72 static int hf_h263_vmv1 = -1;
  73 static int hf_h263_hmv2 = -1;
  74 static int hf_h263_vmv2 = -1;
  75
  76 static int hf_h263_data        = -1;
  77
  78 /* Source format types */
  79 #define SRCFORMAT_FORB   0  /* forbidden */
  80 #define SRCFORMAT_SQCIF  1
  81 #define SRCFORMAT_QCIF   2
  82 #define SRCFORMAT_CIF    3
  83 #define SRCFORMAT_4CIF   4
  84 #define SRCFORMAT_16CIF  5
  85
  86 static const value_string srcformat_vals[] =
  87 {
  88   { SRCFORMAT_FORB,     "forbidden" },
  89   { SRCFORMAT_SQCIF,    "sub-QCIF 128x96" },
  90   { SRCFORMAT_QCIF,     "QCIF 176x144" },
  91   { SRCFORMAT_CIF,      "CIF 352x288" },
  92   { SRCFORMAT_4CIF,     "4CIF 704x576" },
  93   { SRCFORMAT_16CIF,    "16CIF 1408x1152" },
  94   { 0,          NULL },
  95 };
  96
  97 /* H.263 fields defining a sub tree */
  98 static gint ett_h263           = -1;
  99
 100 static void
 101 dissect_h263( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
 102 {
 103         proto_item *ti            = NULL;
 104         proto_tree *h263_tree     = NULL;
 105         unsigned int offset       = 0;
 106         unsigned int h263_version = 0;
 107
 108         h263_version = (tvb_get_guint8( tvb, offset ) & 0xc0 ) >> 6;
 109
 110         if ( check_col( pinfo->cinfo, COL_PROTOCOL ) )   {
 111                 col_set_str( pinfo->cinfo, COL_PROTOCOL, "H.263" );
 112         }
 113
 114         if( h263_version == 0x00) {
 115           if ( check_col( pinfo->cinfo, COL_INFO) ) {
 116             col_append_str( pinfo->cinfo, COL_INFO, " MODE A");
 117           }
 118         }
 119         else if( h263_version == 0x02) {
 120           if ( check_col( pinfo->cinfo, COL_INFO) ) {
 121             col_append_str( pinfo->cinfo, COL_INFO, " MODE B");
 122           }
 123         }
 124         else if( h263_version == 0x03) {
 125           if ( check_col( pinfo->cinfo, COL_INFO) ) {
 126             col_append_str( pinfo->cinfo, COL_INFO, " MODE C");
 127           }
 128         }
 129
 130         if ( tree ) {
 131           ti = proto_tree_add_item( tree, proto_h263, tvb, offset, -1, FALSE );
 132           h263_tree = proto_item_add_subtree( ti, ett_h263 );
 133
 134           /* FBIT 1st octet, 1 bit */
 135           proto_tree_add_boolean( h263_tree, hf_h263_ftype, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x80 );
 136           /* PBIT 1st octet, 1 bit */
 137           proto_tree_add_boolean( h263_tree, hf_h263_pbframes, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x40 );
 138           /* SBIT 1st octet, 3 bits */
 139           proto_tree_add_uint( h263_tree, hf_h263_sbit, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x38 ) >> 3 );
 140           /* EBIT 1st octet, 3 bits */
 141           proto_tree_add_uint( h263_tree, hf_h263_ebit, tvb, offset, 1, tvb_get_guint8( tvb, offset )  & 0x7 );
 142
 143           offset++;
 144
 145           /* SRC 2nd octet, 3 bits */
 146           proto_tree_add_uint( h263_tree, hf_h263_srcformat, tvb, offset, 1, tvb_get_guint8( tvb, offset ) >> 5 );
 147
 148           if(h263_version == 0x00) { /* MODE A */
 149             /* I flag, 1 bit */
 150             proto_tree_add_boolean( h263_tree, hf_h263_picture_coding_type, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x10 );
 151             /* U flag, 1 bit */
 152             proto_tree_add_boolean( h263_tree, hf_h263_unrestricted_motion_vector, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x08 );
 153             /* S flag, 1 bit */
 154             proto_tree_add_boolean( h263_tree, hf_h263_syntax_based_arithmetic, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x04 );
 155             /* A flag, 1 bit */
 156             proto_tree_add_boolean( h263_tree, hf_h263_advanced_prediction, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x02 );
 157
 158             /* Reserved 2nd octect, 1 bit + 3rd octect 3 bits */
 159             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 ) );
 160
 161             offset++;
 162
 163             /* DBQ 3 octect, 2 bits */
 164             proto_tree_add_uint( h263_tree, hf_h263_dbq, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x18 ) >> 3 );
 165             /* TRB 3 octect, 3 bits */
 166             proto_tree_add_uint( h263_tree, hf_h263_trb, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x07 ) );
 167
 168             offset++;
 169
 170             /* TR 4 octect, 8 bits */
 171             proto_tree_add_uint( h263_tree, hf_h263_tr, tvb, offset, 1, tvb_get_guint8( tvb, offset ) );
 172
 173             offset++;
 174
 175           } else { /* MODE B or MODE C */
 176
 177             /* QUANT 2 octect, 5 bits */
 178             proto_tree_add_uint( h263_tree, hf_h263_quant, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x1f );
 179
 180             offset++;
 181
 182             /* GOBN 3 octect, 5 bits */
 183             proto_tree_add_uint( h263_tree, hf_h263_gobn, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0xf8 ) >> 3);
 184             /* MBA 3 octect, 3 bits + 4 octect 6 bits */
 185             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 ) );
 186
 187             offset++;
 188
 189             /* Reserved 4th octect, 2 bits */
 190             proto_tree_add_uint( h263_tree, hf_h263_r, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x3 ) );
 191
 192             offset++;
 193
 194             /* I flag, 1 bit */
 195             proto_tree_add_boolean( h263_tree, hf_h263_picture_coding_type, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x80 );
 196             /* U flag, 1 bit */
 197             proto_tree_add_boolean( h263_tree, hf_h263_unrestricted_motion_vector, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x40 );
 198             /* S flag, 1 bit */
 199             proto_tree_add_boolean( h263_tree, hf_h263_syntax_based_arithmetic, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x20 );
 200             /* A flag, 1 bit */
 201             proto_tree_add_boolean( h263_tree, hf_h263_advanced_prediction, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x10 );
 202
 203             /* HMV1 5th octect, 4 bits + 6th octect 3 bits*/
 204             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) );
 205
 206             offset++;
 207
 208             /* VMV1 6th octect, 5 bits + 7th octect 2 bits*/
 209             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) );
 210
 211             offset++;
 212
 213             /* HMV2 7th octect, 6 bits + 8th octect 1 bit*/
 214             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) );
 215
 216             offset++;
 217
 218             /* VMV2 8th octect, 7 bits*/
 219             proto_tree_add_uint( h263_tree, hf_h263_vmv2, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x7f );
 220
 221             offset++;
 222
 223             if(h263_version == 0x03) { /* MODE C */
 224               /* Reserved 9th to 11th octect, 8 + 8 + 3 bits */
 225               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 ) );
 226
 227               offset+=2;
 228
 229               /* DBQ 11th octect, 2 bits */
 230               proto_tree_add_uint( h263_tree, hf_h263_dbq, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x18 ) >>3 );
 231               /* TRB 11th octect, 3 bits */
 232               proto_tree_add_uint( h263_tree, hf_h263_trb, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x07 );
 233
 234               offset++;
 235
 236               /* TR 12th octect, 8 bits */
 237               proto_tree_add_uint( h263_tree, hf_h263_tr, tvb, offset, 1, tvb_get_guint8( tvb, offset ) );
 238
 239               offset++;
 240             } /* end mode c */
 241           } /* end not mode a */
 242
 243           /* The rest of the packet is the H.263 stream */
 244           proto_tree_add_item( h263_tree, hf_h263_data, tvb, offset, -1, FALSE );
 245         }
 246 }
 247
 248 void
 249 proto_register_h263(void)
 250 {
 251         static hf_register_info hf[] =
 252         {
 253                 {
 254                         &hf_h263_ftype,
 255                         {
 256                                 "F",
 257                                 "h263.sbit",
 258                                 FT_BOOLEAN,
 259                                 BASE_NONE,
 260                                 NULL,
 261                                 0x0,
 262                                 "Indicates the mode of the payload header (MODE A or B/C)", HFILL
 263                         }
 264                 },
 265                 {
 266                         &hf_h263_pbframes,
 267                         {
 268                                 "p/b frame",
 269                                 "h263.pbframes",
 270                                 FT_BOOLEAN,
 271                                 BASE_NONE,
 272                                 NULL,
 273                                 0x0,
 274                                 "Optional PB-frames mode as defined by H.263 (MODE C)", HFILL
 275                         }
 276                 },
 277                 {
 278                         &hf_h263_sbit,
 279                         {
 280                                 "Start bit position",
 281                                 "h263.sbit",
 282                                 FT_UINT8,
 283                                 BASE_DEC,
 284                                 NULL,
 285                                 0x0,
 286                                 "Start bit position specifies number of most significant bits that shall be ignored in the first data byte.", HFILL
 287                         }
 288                 },
 289                 {
 290                         &hf_h263_ebit,
 291                         {
 292                                 "End bit position",
 293                                 "h263.ebit",
 294                                 FT_UINT8,
 295                                 BASE_DEC,
 296                                 NULL,
 297                                 0x0,
 298                                 "End bit position specifies number of least significant bits that shall be ignored in the last data byte.", HFILL
 299                         }
 300                 },
 301                 {
 302                         &hf_h263_srcformat,
 303                         {
 304                                 "SRC format",
 305                                 "h263.srcformat",
 306                                 FT_UINT8,
 307                                 BASE_DEC,
 308                                 VALS(srcformat_vals),
 309                                 0x0,
 310                                 "Source format specifies the resolution of the current picture.", HFILL
 311                         }
 312                 },
 313                 {
 314                         &hf_h263_picture_coding_type,
 315                         {
 316                                 "Inter-coded frame",
 317                                 "h263.picture_coding_type",
 318                                 FT_BOOLEAN,
 319                                 BASE_NONE,
 320                                 NULL,
 321                                 0x0,
 322                                 "Picture coding type, intra-coded (false) or inter-coded (true)", HFILL
 323                         }
 324                 },
 325                 {
 326                         &hf_h263_unrestricted_motion_vector,
 327                         {
 328                                 "Motion vector",
 329                                 "h263.unrestricted_motion_vector",
 330                                 FT_BOOLEAN,
 331                                 BASE_NONE,
 332                                 NULL,
 333                                 0x0,
 334                                 "Unrestricted Motion Vector option for current picture", HFILL
 335                         }
 336                 },
 337                 {
 338                         &hf_h263_syntax_based_arithmetic,
 339                         {
 340                                 "Syntax-based arithmetic coding",
 341                                 "h263.syntax_based_arithmetic",
 342                                 FT_BOOLEAN,
 343                                 BASE_NONE,
 344                                 NULL,
 345                                 0x0,
 346                                 "Syntax-based Arithmetic Coding option for current picture", HFILL
 347                         }
 348                 },
 349                 {
 350                         &hf_h263_advanced_prediction,
 351                         {
 352                                 "Advanced prediction option",
 353                                 "h263.advanced_prediction",
 354                                 FT_BOOLEAN,
 355                                 BASE_NONE,
 356                                 NULL,
 357                                 0x0,
 358                                 "Advanced Prediction option for current picture", HFILL
 359                         }
 360                 },
 361                 {
 362                         &hf_h263_dbq,
 363                         {
 364                                 "Differential quantization parameter",
 365                                 "h263.dbq",
 366                                 FT_UINT8,
 367                                 BASE_DEC,
 368                                 NULL,
 369                                 0x0,
 370                                 "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
 371                         }
 372                 },
 373                 {
 374                         &hf_h263_trb,
 375                         {
 376                                 "Temporal Reference for B frames",
 377                                 "h263.trb",
 378                                 FT_UINT8,
 379                                 BASE_DEC,
 380                                 NULL,
 381                                 0x0,
 382                                 "Temporal Reference for the B frame as defined by H.263", HFILL
 383                         }
 384                 },
 385                 {
 386                         &hf_h263_tr,
 387                         {
 388                                 "Temporal Reference for P frames",
 389                                 "h263.tr",
 390                                 FT_UINT8,
 391                                 BASE_DEC,
 392                                 NULL,
 393                                 0x0,
 394                                 "Temporal Reference for the P frame as defined by H.263", HFILL
 395                         }
 396                 },
 397                 {
 398                         &hf_h263_quant,
 399                         {
 400                                 "Quantizer",
 401                                 "h263.quant",
 402                                 FT_UINT8,
 403                                 BASE_DEC,
 404                                 NULL,
 405                                 0x0,
 406                                 "Quantization value for the first MB coded at the starting of the packet.", HFILL
 407                         }
 408                 },
 409                 {
 410                         &hf_h263_gobn,
 411                         {
 412                                 "GOB Number",
 413                                 "h263.gobn",
 414                                 FT_UINT8,
 415                                 BASE_DEC,
 416                                 NULL,
 417                                 0x0,
 418                                 "GOB number in effect at the start of the packet.", HFILL
 419                         }
 420                 },
 421                 {
 422                         &hf_h263_mba,
 423                         {
 424                                 "Macroblock address",
 425                                 "h263.mba",
 426                                 FT_UINT16,
 427                                 BASE_DEC,
 428                                 NULL,
 429                                 0x0,
 430                                 "The address within the GOB of the first MB in the packet, counting from zero in scan order.", HFILL
 431                         }
 432                 },
 433                 {
 434                         &hf_h263_hmv1,
 435                         {
 436                                 "Horizontal motion vector 1",
 437                                 "h263.hmv1",
 438                                 FT_UINT8,
 439                                 BASE_DEC,
 440                                 NULL,
 441                                 0x0,
 442                                 "Horizontal motion vector predictor for the first MB in this packet ", HFILL
 443                         }
 444                 },
 445                 {
 446                         &hf_h263_vmv1,
 447                         {
 448                                 "Vertical motion vector 1",
 449                                 "h263.vmv1",
 450                                 FT_UINT8,
 451                                 BASE_DEC,
 452                                 NULL,
 453                                 0x0,
 454                                 "Vertical motion vector predictor for the first MB in this packet ", HFILL
 455                         }
 456                 },
 457                 {
 458                         &hf_h263_hmv2,
 459                         {
 460                                 "Horizontal motion vector 2",
 461                                 "h263.hmv2",
 462                                 FT_UINT8,
 463                                 BASE_DEC,
 464                                 NULL,
 465                                 0x0,
 466                                 "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
 467                         }
 468                 },
 469                 {
 470                         &hf_h263_vmv2,
 471                         {
 472                                 "Vertical motion vector 2",
 473                                 "h263.vmv2",
 474                                 FT_UINT8,
 475                                 BASE_DEC,
 476                                 NULL,
 477                                 0x0,
 478                                 "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
 479                         }
 480                 },
 481                 {
 482                         &hf_h263_r,
 483                         {
 484                                 "Reserved field",
 485                                 "h263.r",
 486                                 FT_UINT8,
 487                                 BASE_DEC,
 488                                 NULL,
 489                                 0x0,
 490                                 "Reserved field that houls contain zeroes", HFILL
 491                         }
 492                 },
 493                 {
 494                         &hf_h263_rr,
 495                         {
 496                                 "Reserved field 2",
 497                                 "h263.rr",
 498                                 FT_UINT16,
 499                                 BASE_DEC,
 500                                 NULL,
 501                                 0x0,
 502                                 "Reserved field that should contain zeroes", HFILL
 503                         }
 504                 },
 505                 {
 506                         &hf_h263_data,
 507                         {
 508                                 "H.263 stream",
 509                                 "h263.stream",
 510                                 FT_BYTES,
 511                                 BASE_NONE,
 512                                 NULL,
 513                                 0x0,
 514                                 "The H.263 stream including its Picture, GOB or Macro block start code.", HFILL
 515                         }
 516                 },
 517 };
 518
 519         static gint *ett[] =
 520         {
 521                 &ett_h263,
 522         };
 523
 524
 525         proto_h263 = proto_register_protocol("ITU-T Recommendation H.263 RTP Payload header (RFC2190)",
 526             "H.263", "h263");
 527         proto_register_field_array(proto_h263, hf, array_length(hf));
 528         proto_register_subtree_array(ett, array_length(ett));
 529 }
 530
 531 void
 532 proto_reg_handoff_h263(void)
 533 {
 534         dissector_handle_t h263_handle;
 535
 536         h263_handle = create_dissector_handle(dissect_h263, proto_h263);
 537         dissector_add("rtp.pt", PT_H263, h263_handle);
 538 }