1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
|
/* packet-rfc2190.c
*
* Routines for RFC2190-encapsulated H.263 dissection
*
* Copyright 2003 Niklas Ogren <niklas.ogren@7l.se>
* Seven Levels Consultants AB
*
* Copyright 2008 Richard van der Hoff, MX Telecom
* <richardv@mxtelecom.com>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
/*
* This dissector tries to dissect the H.263 protocol according to
* RFC 2190, https://www.ietf.org/rfc/rfc2190
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/rtp_pt.h>
#include <epan/iax2_codec_type.h>
#include "packet-h263.h"
void proto_register_rfc2190(void);
void proto_reg_handoff_rfc2190(void);
/* H.263 header fields */
static int proto_rfc2190;
/* Mode A header */
static int hf_rfc2190_ftype;
static int hf_rfc2190_pbframes;
static int hf_rfc2190_sbit;
static int hf_rfc2190_ebit;
static int hf_rfc2190_srcformat;
static int hf_rfc2190_picture_coding_type_modeA;
static int hf_rfc2190_unrestricted_motion_vector_modeA;
static int hf_rfc2190_syntax_based_arithmetic_modeA;
static int hf_rfc2190_advanced_prediction_modeA;
static int hf_rfc2190_r_modeA;
static int hf_rfc2190_rr;
static int hf_rfc2190_dbq;
static int hf_rfc2190_trb;
static int hf_rfc2190_tr;
/* Additional fields for Mode B or C header */
static int hf_rfc2190_picture_coding_type_modeB;
static int hf_rfc2190_unrestricted_motion_vector_modeB;
static int hf_rfc2190_syntax_based_arithmetic_modeB;
static int hf_rfc2190_advanced_prediction_modeB;
static int hf_rfc2190_r_modeB;
static int hf_rfc2190_quant;
static int hf_rfc2190_gobn;
static int hf_rfc2190_mba;
static int hf_rfc2190_hmv1;
static int hf_rfc2190_vmv1;
static int hf_rfc2190_hmv2;
static int hf_rfc2190_vmv2;
static int ett_rfc2190;
static dissector_handle_t h263_handle;
static dissector_handle_t rfc2190_handle;
static int
dissect_rfc2190( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_ )
{
proto_item *ti = NULL;
proto_tree *rfc2190_tree = NULL;
int offset = 0;
unsigned int rfc2190_version = 0;
tvbuff_t *next_tvb;
int hdr_len = 0;
rfc2190_version = (tvb_get_uint8( tvb, offset ) & 0xc0 ) >> 6;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "H.263 ");
/* Three formats (mode A, mode B and mode C) are defined for H.263
* payload header. In mode A, an H.263 payload header of four bytes is
* present before actual compressed H.263 video bitstream in a packet.
* It allows fragmentation at GOB boundaries. In mode B, an eight byte
* H.263 payload header is used and each packet starts at MB boundaries
* without the PB-frames option. Finally, a twelve byte H.263 payload
* header is defined in mode C to support fragmentation at MB boundaries
* for frames that are coded with the PB-frames option.
*/
if( rfc2190_version == 0x00) {
col_append_str( pinfo->cinfo, COL_INFO, "MODE A ");
hdr_len = 4;
}
else if( rfc2190_version == 0x02) {
col_append_str( pinfo->cinfo, COL_INFO, "MODE B ");
hdr_len = 8;
}
else if( rfc2190_version == 0x03) {
col_append_str( pinfo->cinfo, COL_INFO, "MODE C ");
hdr_len = 12;
}
if ( tree ) {
ti = proto_tree_add_item( tree, proto_rfc2190, tvb, offset, hdr_len, ENC_NA );
rfc2190_tree = proto_item_add_subtree( ti, ett_rfc2190 );
/* FBIT 1st octet, 1 bit */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_ftype, tvb, offset, 1, ENC_BIG_ENDIAN );
/* PBIT 1st octet, 1 bit */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_pbframes, tvb, offset, 1, ENC_BIG_ENDIAN );
/* SBIT 1st octet, 3 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_sbit, tvb, offset, 1, ENC_BIG_ENDIAN );
/* EBIT 1st octet, 3 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_ebit, tvb, offset, 1, ENC_BIG_ENDIAN );
offset++;
/* SRC 2nd octet, 3 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_srcformat, tvb, offset, 1, ENC_BIG_ENDIAN );
if(rfc2190_version == 0x00) { /* MODE A */
/* I flag, 1 bit */
proto_tree_add_item(rfc2190_tree, hf_rfc2190_picture_coding_type_modeA, tvb, offset, 1, ENC_BIG_ENDIAN);
/* U flag, 1 bit */
proto_tree_add_item(rfc2190_tree, hf_rfc2190_unrestricted_motion_vector_modeA, tvb, offset, 1, ENC_BIG_ENDIAN);
/* S flag, 1 bit */
proto_tree_add_item(rfc2190_tree, hf_rfc2190_syntax_based_arithmetic_modeA, tvb, offset, 1, ENC_BIG_ENDIAN);
/* A flag, 1 bit */
proto_tree_add_item(rfc2190_tree, hf_rfc2190_advanced_prediction_modeA, tvb, offset, 1, ENC_BIG_ENDIAN);
/* Reserved 2nd octet, 1 bit + 3rd octet 3 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_r_modeA, tvb, offset, 2, ENC_BIG_ENDIAN);
offset++;
/* DBQ 3 octet, 2 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_dbq, tvb, offset, 1, ENC_BIG_ENDIAN );
/* TRB 3 octet, 3 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_trb, tvb, offset, 1, ENC_BIG_ENDIAN );
offset++;
/* TR 4 octet, 8 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_tr, tvb, offset, 1, ENC_NA );
offset++;
} else { /* MODE B or MODE C */
/* QUANT 2 octet, 5 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_quant, tvb, offset, 1, ENC_NA);
offset++;
/* GOBN 3 octet, 5 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_gobn, tvb, offset, 1, ENC_NA);
/* MBA 3 octet, 3 bits + 4 octet 6 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_mba, tvb, offset, 2, ENC_BIG_ENDIAN );
offset++;
/* Reserved 4th octet, 2 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_r_modeB, tvb, offset, 1, ENC_NA);
offset++;
/* I flag, 1 bit */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_picture_coding_type_modeB, tvb, offset, 1, ENC_BIG_ENDIAN);
/* U flag, 1 bit */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_unrestricted_motion_vector_modeB, tvb, offset, 1, ENC_BIG_ENDIAN);
/* S flag, 1 bit */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_syntax_based_arithmetic_modeB, tvb, offset, 1, ENC_BIG_ENDIAN);
/* A flag, 1 bit */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_advanced_prediction_modeB, tvb, offset, 1, ENC_BIG_ENDIAN);
/* HMV1 5th octet, 4 bits + 6th octet 3 bits*/
proto_tree_add_item( rfc2190_tree, hf_rfc2190_hmv1, tvb, offset, 2, ENC_BIG_ENDIAN);
offset++;
/* VMV1 6th octet, 5 bits + 7th octet 2 bits*/
proto_tree_add_item( rfc2190_tree, hf_rfc2190_vmv1, tvb, offset, 2, ENC_BIG_ENDIAN);
offset++;
/* HMV2 7th octet, 6 bits + 8th octet 1 bit*/
proto_tree_add_item( rfc2190_tree, hf_rfc2190_hmv2, tvb, offset, 2, ENC_BIG_ENDIAN);
offset++;
/* VMV2 8th octet, 7 bits*/
proto_tree_add_item( rfc2190_tree, hf_rfc2190_vmv2, tvb, offset, 1, ENC_NA);
offset++;
if(rfc2190_version == 0x03) { /* MODE C */
/* Reserved 9th to 11th octet, 8 + 8 + 3 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_rr, tvb, offset, 3, ENC_BIG_ENDIAN);
offset+=2;
/* DBQ 11th octet, 2 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_dbq, tvb, offset, 1, ENC_BIG_ENDIAN );
/* TRB 11th octet, 3 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_trb, tvb, offset, 1, ENC_BIG_ENDIAN );
offset++;
/* TR 12th octet, 8 bits */
proto_tree_add_item( rfc2190_tree, hf_rfc2190_tr, tvb, offset, 1, ENC_NA );
offset++;
} /* end mode c */
} /* end not mode a */
} else {
switch(rfc2190_version) {
case 0x00: /* MODE A */
offset += 4;
break;
case 0x01: /* MODE B */
offset += 8;
break;
case 0x02: /* MODE C */
offset += 12;
break;
}
}
/* The rest of the packet is the H.263 stream */
next_tvb = tvb_new_subset_remaining( tvb, offset);
call_dissector(h263_handle,next_tvb,pinfo,tree);
return tvb_captured_length(tvb);
}
void
proto_reg_handoff_rfc2190(void)
{
dissector_add_uint("rtp.pt", PT_H263, rfc2190_handle);
dissector_add_uint("iax2.codec", AST_FORMAT_H263, rfc2190_handle);
h263_handle = find_dissector_add_dependency("h263data", proto_rfc2190);
}
void
proto_register_rfc2190(void)
{
static hf_register_info hf[] = {
{
&hf_rfc2190_ftype,
{
"F",
"rfc2190.ftype",
FT_BOOLEAN,
8,
NULL,
0x80,
"Indicates the mode of the payload header (MODE A or B/C)", HFILL
}
},
{
&hf_rfc2190_pbframes,
{
"p/b frame",
"rfc2190.pbframes",
FT_BOOLEAN,
8,
NULL,
0x40,
"Optional PB-frames mode as defined by H.263 (MODE C)", HFILL
}
},
{
&hf_rfc2190_sbit,
{
"Start bit position",
"rfc2190.sbit",
FT_UINT8,
BASE_DEC,
NULL,
0x38,
"Start bit position specifies number of most significant bits that shall be ignored in the first data byte.", HFILL
}
},
{
&hf_rfc2190_ebit,
{
"End bit position",
"rfc2190.ebit",
FT_UINT8,
BASE_DEC,
NULL,
0x7,
"End bit position specifies number of least significant bits that shall be ignored in the last data byte.", HFILL
}
},
{
&hf_rfc2190_srcformat,
{
"SRC format",
"rfc2190.srcformat",
FT_UINT8,
BASE_DEC,
VALS(h263_srcformat_vals),
0xe0,
"Source format specifies the resolution of the current picture.", HFILL
}
},
{
&hf_rfc2190_picture_coding_type_modeA,
{
"Inter-coded frame",
"rfc2190.picture_coding_type",
FT_BOOLEAN,
8,
NULL,
0x10,
"Picture coding type, intra-coded (false) or inter-coded (true)", HFILL
}
},
{
&hf_rfc2190_unrestricted_motion_vector_modeA,
{
"Motion vector",
"rfc2190.unrestricted_motion_vector",
FT_BOOLEAN,
8,
NULL,
0x08,
"Unrestricted Motion Vector option for current picture", HFILL
}
},
{
&hf_rfc2190_syntax_based_arithmetic_modeA,
{
"Syntax-based arithmetic coding",
"rfc2190.syntax_based_arithmetic",
FT_BOOLEAN,
8,
NULL,
0x04,
"Syntax-based Arithmetic Coding option for current picture", HFILL
}
},
{
&hf_rfc2190_advanced_prediction_modeA,
{
"Advanced prediction option",
"rfc2190.advanced_prediction",
FT_BOOLEAN,
8,
NULL,
0x02,
"Advanced Prediction option for current picture", HFILL
}
},
{
&hf_rfc2190_picture_coding_type_modeB,
{
"Inter-coded frame",
"rfc2190.picture_coding_type",
FT_BOOLEAN,
8,
NULL,
0x80,
"Picture coding type, intra-coded (false) or inter-coded (true)", HFILL
}
},
{
&hf_rfc2190_unrestricted_motion_vector_modeB,
{
"Motion vector",
"rfc2190.unrestricted_motion_vector",
FT_BOOLEAN,
8,
NULL,
0x40,
"Unrestricted Motion Vector option for current picture", HFILL
}
},
{
&hf_rfc2190_syntax_based_arithmetic_modeB,
{
"Syntax-based arithmetic coding",
"rfc2190.syntax_based_arithmetic",
FT_BOOLEAN,
8,
NULL,
0x20,
"Syntax-based Arithmetic Coding option for current picture", HFILL
}
},
{
&hf_rfc2190_advanced_prediction_modeB,
{
"Advanced prediction option",
"rfc2190.advanced_prediction",
FT_BOOLEAN,
8,
NULL,
0x10,
"Advanced Prediction option for current picture", HFILL
}
},
{
&hf_rfc2190_dbq,
{
"Differential quantization parameter",
"rfc2190.dbq",
FT_UINT8,
BASE_DEC,
NULL,
0x18,
"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
}
},
{
&hf_rfc2190_trb,
{
"Temporal Reference for B frames",
"rfc2190.trb",
FT_UINT8,
BASE_DEC,
NULL,
0x07,
"Temporal Reference for the B frame as defined by H.263", HFILL
}
},
{
&hf_rfc2190_tr,
{
"Temporal Reference for P frames",
"rfc2190.tr",
FT_UINT8,
BASE_DEC,
NULL,
0x0,
"Temporal Reference for the P frame as defined by H.263", HFILL
}
},
{
&hf_rfc2190_quant,
{
"Quantizer",
"rfc2190.quant",
FT_UINT8,
BASE_DEC,
NULL,
0x1F,
"Quantization value for the first MB coded at the starting of the packet.", HFILL
}
},
{
&hf_rfc2190_gobn,
{
"GOB Number",
"rfc2190.gobn",
FT_UINT8,
BASE_DEC,
NULL,
0xF8,
"GOB number in effect at the start of the packet.", HFILL
}
},
{
&hf_rfc2190_mba,
{
"Macroblock address",
"rfc2190.mba",
FT_UINT16,
BASE_DEC,
NULL,
0x3FE0,
"The address within the GOB of the first MB in the packet, counting from zero in scan order.", HFILL
}
},
{
&hf_rfc2190_hmv1,
{
"Horizontal motion vector 1",
"rfc2190.hmv1",
FT_UINT16,
BASE_DEC,
NULL,
0x0FE0,
"Horizontal motion vector predictor for the first MB in this packet", HFILL
}
},
{
&hf_rfc2190_vmv1,
{
"Vertical motion vector 1",
"rfc2190.vmv1",
FT_UINT16,
BASE_DEC,
NULL,
0x01FC,
"Vertical motion vector predictor for the first MB in this packet", HFILL
}
},
{
&hf_rfc2190_hmv2,
{
"Horizontal motion vector 2",
"rfc2190.hmv2",
FT_UINT16,
BASE_DEC,
NULL,
0x03F8,
"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
}
},
{
&hf_rfc2190_vmv2,
{
"Vertical motion vector 2",
"rfc2190.vmv2",
FT_UINT8,
BASE_DEC,
NULL,
0x7F,
"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
}
},
{
&hf_rfc2190_r_modeA,
{
"Reserved field",
"rfc2190.r",
FT_UINT16,
BASE_DEC,
NULL,
0x01E0,
"Reserved field that should contain zeroes", HFILL
}
},
{
&hf_rfc2190_r_modeB,
{
"Reserved field",
"rfc2190.r",
FT_UINT8,
BASE_DEC,
NULL,
0x03,
"Reserved field that should contain zeroes", HFILL
}
},
{
&hf_rfc2190_rr,
{
"Reserved field 2",
"rfc2190.rr",
FT_UINT24,
BASE_DEC,
NULL,
0x07FFFF,
"Reserved field that should contain zeroes", HFILL
}
},
};
static int *ett[] = {
&ett_rfc2190,
};
proto_register_subtree_array(ett, array_length(ett));
proto_rfc2190 = proto_register_protocol("H.263 RTP Payload header (RFC2190)",
"H.263 (RFC2190)", "rfc2190");
proto_register_field_array(proto_rfc2190, hf, array_length(hf));
rfc2190_handle = register_dissector("rfc2190", dissect_rfc2190, proto_rfc2190);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
|
