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  * 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 #include "iax2_codec_type.h"
  49
  50 /* H.263 header fields             */
  51 static int proto_h263          = -1;
  52
  53 /* Mode A header */
  54 static int hf_h263_ftype = -1;
  55 static int hf_h263_pbframes = -1;
  56 static int hf_h263_sbit = -1;
  57 static int hf_h263_ebit = -1;
  58 static int hf_h263_srcformat = -1;
  59 static int hf_h263_picture_coding_type = -1;
  60 static int hf_h263_unrestricted_motion_vector = -1;
  61 static int hf_h263_syntax_based_arithmetic = -1;
  62 static int hf_h263_advanced_prediction = -1;
  63 static int hf_h263_r = -1;
  64 static int hf_h263_rr = -1;
  65 static int hf_h263_dbq = -1;
  66 static int hf_h263_trb = -1;
  67 static int hf_h263_tr = -1;
  68 /* Additional fields for Mode B or C header */
  69 static int hf_h263_quant = -1;
  70 static int hf_h263_gobn = -1;
  71 static int hf_h263_mba = -1;
  72 static int hf_h263_hmv1 = -1;
  73 static int hf_h263_vmv1 = -1;
  74 static int hf_h263_hmv2 = -1;
  75 static int hf_h263_vmv2 = -1;
  76
  77 static int hf_h263_data        = -1;
  78
  79 /* Source format types */
  80 #define SRCFORMAT_FORB   0  /* forbidden */
  81 #define SRCFORMAT_SQCIF  1
  82 #define SRCFORMAT_QCIF   2
  83 #define SRCFORMAT_CIF    3
  84 #define SRCFORMAT_4CIF   4
  85 #define SRCFORMAT_16CIF  5
  86
  87 static const value_string srcformat_vals[] =
  88 {
  89   { SRCFORMAT_FORB,     "forbidden" },
  90   { SRCFORMAT_SQCIF,    "sub-QCIF 128x96" },
  91   { SRCFORMAT_QCIF,     "QCIF 176x144" },
  92   { SRCFORMAT_CIF,      "CIF 352x288" },
  93   { SRCFORMAT_4CIF,     "4CIF 704x576" },
  94   { SRCFORMAT_16CIF,    "16CIF 1408x1152" },
  95   { 0,          NULL },
  96 };
  97
  98 /* H.263 fields defining a sub tree */
  99 static gint ett_h263           = -1;
 100
 101 static void
 102 dissect_h263( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
 103 {
 104         proto_item *ti            = NULL;
 105         proto_tree *h263_tree     = NULL;
 106         unsigned int offset       = 0;
 107         unsigned int h263_version = 0;
 108
 109         h263_version = (tvb_get_guint8( tvb, offset ) & 0xc0 ) >> 6;
 110
 111         if ( check_col( pinfo->cinfo, COL_PROTOCOL ) )   {
 112                 col_set_str( pinfo->cinfo, COL_PROTOCOL, "H.263" );
 113         }
 114
 115         if( h263_version == 0x00) {
 116           if ( check_col( pinfo->cinfo, COL_INFO) ) {
 117             col_append_str( pinfo->cinfo, COL_INFO, " MODE A");
 118           }
 119         }
 120         else if( h263_version == 0x02) {
 121           if ( check_col( pinfo->cinfo, COL_INFO) ) {
 122             col_append_str( pinfo->cinfo, COL_INFO, " MODE B");
 123           }
 124         }
 125         else if( h263_version == 0x03) {
 126           if ( check_col( pinfo->cinfo, COL_INFO) ) {
 127             col_append_str( pinfo->cinfo, COL_INFO, " MODE C");
 128           }
 129         }
 130
 131         if ( tree ) {
 132           ti = proto_tree_add_item( tree, proto_h263, tvb, offset, -1, FALSE );
 133           h263_tree = proto_item_add_subtree( ti, ett_h263 );
 134
 135           /* FBIT 1st octet, 1 bit */
 136           proto_tree_add_boolean( h263_tree, hf_h263_ftype, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x80 );
 137           /* PBIT 1st octet, 1 bit */
 138           proto_tree_add_boolean( h263_tree, hf_h263_pbframes, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x40 );
 139           /* SBIT 1st octet, 3 bits */
 140           proto_tree_add_uint( h263_tree, hf_h263_sbit, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x38 ) >> 3 );
 141           /* EBIT 1st octet, 3 bits */
 142           proto_tree_add_uint( h263_tree, hf_h263_ebit, tvb, offset, 1, tvb_get_guint8( tvb, offset )  & 0x7 );
 143
 144           offset++;
 145
 146           /* SRC 2nd octet, 3 bits */
 147           proto_tree_add_uint( h263_tree, hf_h263_srcformat, tvb, offset, 1, tvb_get_guint8( tvb, offset ) >> 5 );
 148
 149           if(h263_version == 0x00) { /* MODE A */
 150             /* I flag, 1 bit */
 151             proto_tree_add_boolean( h263_tree, hf_h263_picture_coding_type, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x10 );
 152             /* U flag, 1 bit */
 153             proto_tree_add_boolean( h263_tree, hf_h263_unrestricted_motion_vector, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x08 );
 154             /* S flag, 1 bit */
 155             proto_tree_add_boolean( h263_tree, hf_h263_syntax_based_arithmetic, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x04 );
 156             /* A flag, 1 bit */
 157             proto_tree_add_boolean( h263_tree, hf_h263_advanced_prediction, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x02 );
 158
 159             /* Reserved 2nd octect, 1 bit + 3rd octect 3 bits */
 160             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 ) );
 161
 162             offset++;
 163
 164             /* DBQ 3 octect, 2 bits */
 165             proto_tree_add_uint( h263_tree, hf_h263_dbq, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x18 ) >> 3 );
 166             /* TRB 3 octect, 3 bits */
 167             proto_tree_add_uint( h263_tree, hf_h263_trb, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x07 ) );
 168
 169             offset++;
 170
 171             /* TR 4 octect, 8 bits */
 172             proto_tree_add_uint( h263_tree, hf_h263_tr, tvb, offset, 1, tvb_get_guint8( tvb, offset ) );
 173
 174             offset++;
 175
 176           } else { /* MODE B or MODE C */
 177
 178             /* QUANT 2 octect, 5 bits */
 179             proto_tree_add_uint( h263_tree, hf_h263_quant, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x1f );
 180
 181             offset++;
 182
 183             /* GOBN 3 octect, 5 bits */
 184             proto_tree_add_uint( h263_tree, hf_h263_gobn, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0xf8 ) >> 3);
 185             /* MBA 3 octect, 3 bits + 4 octect 6 bits */
 186             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 ) );
 187
 188             offset++;
 189
 190             /* Reserved 4th octect, 2 bits */
 191             proto_tree_add_uint( h263_tree, hf_h263_r, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x3 ) );
 192
 193             offset++;
 194
 195             /* I flag, 1 bit */
 196             proto_tree_add_boolean( h263_tree, hf_h263_picture_coding_type, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x80 );
 197             /* U flag, 1 bit */
 198             proto_tree_add_boolean( h263_tree, hf_h263_unrestricted_motion_vector, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x40 );
 199             /* S flag, 1 bit */
 200             proto_tree_add_boolean( h263_tree, hf_h263_syntax_based_arithmetic, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x20 );
 201             /* A flag, 1 bit */
 202             proto_tree_add_boolean( h263_tree, hf_h263_advanced_prediction, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x10 );
 203
 204             /* HMV1 5th octect, 4 bits + 6th octect 3 bits*/
 205             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) );
 206
 207             offset++;
 208
 209             /* VMV1 6th octect, 5 bits + 7th octect 2 bits*/
 210             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) );
 211
 212             offset++;
 213
 214             /* HMV2 7th octect, 6 bits + 8th octect 1 bit*/
 215             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) );
 216
 217             offset++;
 218
 219             /* VMV2 8th octect, 7 bits*/
 220             proto_tree_add_uint( h263_tree, hf_h263_vmv2, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x7f );
 221
 222             offset++;
 223
 224             if(h263_version == 0x03) { /* MODE C */
 225               /* Reserved 9th to 11th octect, 8 + 8 + 3 bits */
 226               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 ) );
 227
 228               offset+=2;
 229
 230               /* DBQ 11th octect, 2 bits */
 231               proto_tree_add_uint( h263_tree, hf_h263_dbq, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) & 0x18 ) >>3 );
 232               /* TRB 11th octect, 3 bits */
 233               proto_tree_add_uint( h263_tree, hf_h263_trb, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 0x07 );
 234
 235               offset++;
 236
 237               /* TR 12th octect, 8 bits */
 238               proto_tree_add_uint( h263_tree, hf_h263_tr, tvb, offset, 1, tvb_get_guint8( tvb, offset ) );
 239
 240               offset++;
 241             } /* end mode c */
 242           } /* end not mode a */
 243
 244           /* The rest of the packet is the H.263 stream */
 245           proto_tree_add_item( h263_tree, hf_h263_data, tvb, offset, -1, FALSE );
 246         }
 247 }
 248
 249 void
 250 proto_register_h263(void)
 251 {
 252         static hf_register_info hf[] =
 253         {
 254                 {
 255                         &hf_h263_ftype,
 256                         {
 257                                 "F",
 258                                 "h263.sbit",
 259                                 FT_BOOLEAN,
 260                                 BASE_NONE,
 261                                 NULL,
 262                                 0x0,
 263                                 "Indicates the mode of the payload header (MODE A or B/C)", HFILL
 264                         }
 265                 },
 266                 {
 267                         &hf_h263_pbframes,
 268                         {
 269                                 "p/b frame",
 270                                 "h263.pbframes",
 271                                 FT_BOOLEAN,
 272                                 BASE_NONE,
 273                                 NULL,
 274                                 0x0,
 275                                 "Optional PB-frames mode as defined by H.263 (MODE C)", HFILL
 276                         }
 277                 },
 278                 {
 279                         &hf_h263_sbit,
 280                         {
 281                                 "Start bit position",
 282                                 "h263.sbit",
 283                                 FT_UINT8,
 284                                 BASE_DEC,
 285                                 NULL,
 286                                 0x0,
 287                                 "Start bit position specifies number of most significant bits that shall be ignored in the first data byte.", HFILL
 288                         }
 289                 },
 290                 {
 291                         &hf_h263_ebit,
 292                         {
 293                                 "End bit position",
 294                                 "h263.ebit",
 295                                 FT_UINT8,
 296                                 BASE_DEC,
 297                                 NULL,
 298                                 0x0,
 299                                 "End bit position specifies number of least significant bits that shall be ignored in the last data byte.", HFILL
 300                         }
 301                 },
 302                 {
 303                         &hf_h263_srcformat,
 304                         {
 305                                 "SRC format",
 306                                 "h263.srcformat",
 307                                 FT_UINT8,
 308                                 BASE_DEC,
 309                                 VALS(srcformat_vals),
 310                                 0x0,
 311                                 "Source format specifies the resolution of the current picture.", HFILL
 312                         }
 313                 },
 314                 {
 315                         &hf_h263_picture_coding_type,
 316                         {
 317                                 "Inter-coded frame",
 318                                 "h263.picture_coding_type",
 319                                 FT_BOOLEAN,
 320                                 BASE_NONE,
 321                                 NULL,
 322                                 0x0,
 323                                 "Picture coding type, intra-coded (false) or inter-coded (true)", HFILL
 324                         }
 325                 },
 326                 {
 327                         &hf_h263_unrestricted_motion_vector,
 328                         {
 329                                 "Motion vector",
 330                                 "h263.unrestricted_motion_vector",
 331                                 FT_BOOLEAN,
 332                                 BASE_NONE,
 333                                 NULL,
 334                                 0x0,
 335                                 "Unrestricted Motion Vector option for current picture", HFILL
 336                         }
 337                 },
 338                 {
 339                         &hf_h263_syntax_based_arithmetic,
 340                         {
 341                                 "Syntax-based arithmetic coding",
 342                                 "h263.syntax_based_arithmetic",
 343                                 FT_BOOLEAN,
 344                                 BASE_NONE,
 345                                 NULL,
 346                                 0x0,
 347                                 "Syntax-based Arithmetic Coding option for current picture", HFILL
 348                         }
 349                 },
 350                 {
 351                         &hf_h263_advanced_prediction,
 352                         {
 353                                 "Advanced prediction option",
 354                                 "h263.advanced_prediction",
 355                                 FT_BOOLEAN,
 356                                 BASE_NONE,
 357                                 NULL,
 358                                 0x0,
 359                                 "Advanced Prediction option for current picture", HFILL
 360                         }
 361                 },
 362                 {
 363                         &hf_h263_dbq,
 364                         {
 365                                 "Differential quantization parameter",
 366                                 "h263.dbq",
 367                                 FT_UINT8,
 368                                 BASE_DEC,
 369                                 NULL,
 370                                 0x0,
 371                                 "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
 372                         }
 373                 },
 374                 {
 375                         &hf_h263_trb,
 376                         {
 377                                 "Temporal Reference for B frames",
 378                                 "h263.trb",
 379                                 FT_UINT8,
 380                                 BASE_DEC,
 381                                 NULL,
 382                                 0x0,
 383                                 "Temporal Reference for the B frame as defined by H.263", HFILL
 384                         }
 385                 },
 386                 {
 387                         &hf_h263_tr,
 388                         {
 389                                 "Temporal Reference for P frames",
 390                                 "h263.tr",
 391                                 FT_UINT8,
 392                                 BASE_DEC,
 393                                 NULL,
 394                                 0x0,
 395                                 "Temporal Reference for the P frame as defined by H.263", HFILL
 396                         }
 397                 },
 398                 {
 399                         &hf_h263_quant,
 400                         {
 401                                 "Quantizer",
 402                                 "h263.quant",
 403                                 FT_UINT8,
 404                                 BASE_DEC,
 405                                 NULL,
 406                                 0x0,
 407                                 "Quantization value for the first MB coded at the starting of the packet.", HFILL
 408                         }
 409                 },
 410                 {
 411                         &hf_h263_gobn,
 412                         {
 413                                 "GOB Number",
 414                                 "h263.gobn",
 415                                 FT_UINT8,
 416                                 BASE_DEC,
 417                                 NULL,
 418                                 0x0,
 419                                 "GOB number in effect at the start of the packet.", HFILL
 420                         }
 421                 },
 422                 {
 423                         &hf_h263_mba,
 424                         {
 425                                 "Macroblock address",
 426                                 "h263.mba",
 427                                 FT_UINT16,
 428                                 BASE_DEC,
 429                                 NULL,
 430                                 0x0,
 431                                 "The address within the GOB of the first MB in the packet, counting from zero in scan order.", HFILL
 432                         }
 433                 },
 434                 {
 435                         &hf_h263_hmv1,
 436                         {
 437                                 "Horizontal motion vector 1",
 438                                 "h263.hmv1",
 439                                 FT_UINT8,
 440                                 BASE_DEC,
 441                                 NULL,
 442                                 0x0,
 443                                 "Horizontal motion vector predictor for the first MB in this packet ", HFILL
 444                         }
 445                 },
 446                 {
 447                         &hf_h263_vmv1,
 448                         {
 449                                 "Vertical motion vector 1",
 450                                 "h263.vmv1",
 451                                 FT_UINT8,
 452                                 BASE_DEC,
 453                                 NULL,
 454                                 0x0,
 455                                 "Vertical motion vector predictor for the first MB in this packet ", HFILL
 456                         }
 457                 },
 458                 {
 459                         &hf_h263_hmv2,
 460                         {
 461                                 "Horizontal motion vector 2",
 462                                 "h263.hmv2",
 463                                 FT_UINT8,
 464                                 BASE_DEC,
 465                                 NULL,
 466                                 0x0,
 467                                 "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
 468                         }
 469                 },
 470                 {
 471                         &hf_h263_vmv2,
 472                         {
 473                                 "Vertical motion vector 2",
 474                                 "h263.vmv2",
 475                                 FT_UINT8,
 476                                 BASE_DEC,
 477                                 NULL,
 478                                 0x0,
 479                                 "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
 480                         }
 481                 },
 482                 {
 483                         &hf_h263_r,
 484                         {
 485                                 "Reserved field",
 486                                 "h263.r",
 487                                 FT_UINT8,
 488                                 BASE_DEC,
 489                                 NULL,
 490                                 0x0,
 491                                 "Reserved field that houls contain zeroes", HFILL
 492                         }
 493                 },
 494                 {
 495                         &hf_h263_rr,
 496                         {
 497                                 "Reserved field 2",
 498                                 "h263.rr",
 499                                 FT_UINT16,
 500                                 BASE_DEC,
 501                                 NULL,
 502                                 0x0,
 503                                 "Reserved field that should contain zeroes", HFILL
 504                         }
 505                 },
 506                 {
 507                         &hf_h263_data,
 508                         {
 509                                 "H.263 stream",
 510                                 "h263.stream",
 511                                 FT_BYTES,
 512                                 BASE_NONE,
 513                                 NULL,
 514                                 0x0,
 515                                 "The H.263 stream including its Picture, GOB or Macro block start code.", HFILL
 516                         }
 517                 },
 518 };
 519
 520         static gint *ett[] =
 521         {
 522                 &ett_h263,
 523         };
 524
 525
 526         proto_h263 = proto_register_protocol("ITU-T Recommendation H.263 RTP Payload header (RFC2190)",
 527             "H.263", "h263");
 528         proto_register_field_array(proto_h263, hf, array_length(hf));
 529         proto_register_subtree_array(ett, array_length(ett));
 530         register_dissector("h263", dissect_h263, proto_h263);
 531 }
 532
 533 void
 534 proto_reg_handoff_h263(void)
 535 {
 536         dissector_handle_t h263_handle;
 537
 538         h263_handle = find_dissector("h263");
 539         dissector_add("rtp.pt", PT_H263, h263_handle);
 540         dissector_add("iax2.codec", AST_FORMAT_H263, h263_handle);
 541 }