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
|
/* packet-vp9.c
* Routines for VP9 dissection
* Copyright 2023, Noan Perrot <noan.perrot@gmail.com>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
/*
* vp9-bitstream-specification-v0.6-20160331-draft - VP9 Bitstream & Decoding Process Specification
* draft-ietf-payload-vp9-16 - RTP Payload Format for VP9 Video
*/
#include "config.h"
/* Define the name for the logging domain (try to avoid collisions with existing domains) */
#define WS_LOG_DOMAIN "vp9"
/* Global header providing a minimum base set of required macros and APIs */
#include <wireshark.h>
#include <epan/packet.h> /* Required dissection API header */
#include <epan/expert.h> /* Include only as needed */
#include <epan/prefs.h> /* Include only as needed */
#define STRING_SIZE 50
#define VP9_1_BIT_MASK 0x80
#define VP9_2_BIT_MASK 0x40
#define VP9_3_BIT_MASK 0x20
#define VP9_4_BIT_MASK 0x10
#define VP9_5_BIT_MASK 0x08
#define VP9_6_BIT_MASK 0x04
#define VP9_7_BIT_MASK 0x02
#define VP9_8_BIT_MASK 0x01
#define VP9_2_BITS_MASK 0xC0
#define VP9_3_BITS_MASK 0xE0
#define VP9_7_BITS_MASK 0xFE
#define VP9_8_BITS_MASK 0xFF
#define VP9_16_BITS_MASK 0xFFFF
#define VP9_EXTENDED_PID 0x7FFF
static int proto_vp9 = -1;
static int hf_vp9_pld_i_bit = -1;
static int hf_vp9_pld_p_bit = -1;
static int hf_vp9_pld_l_bit = -1;
static int hf_vp9_pld_f_bit = -1;
static int hf_vp9_pld_b_bit = -1;
static int hf_vp9_pld_e_bit = -1;
static int hf_vp9_pld_v_bit = -1;
static int hf_vp9_pld_z_bit = -1;
static int hf_vp9_pld_u_bit = -1;
static int hf_vp9_pld_m_bit = -1;
static int hf_vp9_pld_d_bit = -1;
static int hf_vp9_pld_n_bit = -1;
static int hf_vp9_pld_y_bit = -1;
static int hf_vp9_pld_g_bit = -1;
static int hf_vp9_pld_pg_bits = -1;
static int hf_vp9_pld_n_s_bits = -1;
static int hf_vp9_pld_n_g_bits = -1;
static int hf_vp9_pld_sid_bits = -1;
static int hf_vp9_pld_pid_bits = -1;
static int hf_vp9_pld_tid_bits = -1;
static int hf_vp9_pld_width_bits = -1;
static int hf_vp9_pld_height_bits = -1;
static int hf_vp9_pld_p_diff_bits = -1;
static int hf_vp9_pld_tl0picidx_bits = -1;
static int hf_vp9_pld_pg_extended_bits = -1;
static int hf_vp9_pld_pid_extended_bits = -1;
static int ett_vp9 = -1;
static int ett_vp9_descriptor = -1;
static int *ett[] = {
&ett_vp9,
&ett_vp9_descriptor
};
static int
dissect_vp9(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree _U_, void *data _U_)
{
col_set_str(pinfo->cinfo, COL_PROTOCOL, "VP9");
proto_item *vp9_item = proto_tree_add_item(tree, proto_vp9, tvb, 0, -1, ENC_NA);
proto_tree *vp9_tree = proto_item_add_subtree(vp9_item, ett_vp9);
proto_item *vp9_descriptor_item;
proto_tree *vp9_descriptor_tree = proto_tree_add_subtree(vp9_tree, tvb, 0, 1, ett_vp9_descriptor, &vp9_descriptor_item, "Payload Descriptor");
int offset = 0;
/*
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
|I|P|L|F|B|E|V|Z| (REQUIRED)
+-+-+-+-+-+-+-+-+
*/
guint8 i = tvb_get_guint8(tvb, offset) & VP9_1_BIT_MASK;
guint8 p = tvb_get_guint8(tvb, offset) & VP9_2_BIT_MASK;
guint8 l = tvb_get_guint8(tvb, offset) & VP9_3_BIT_MASK;
guint8 f = tvb_get_guint8(tvb, offset) & VP9_4_BIT_MASK;
guint8 v = tvb_get_guint8(tvb, offset) & VP9_7_BIT_MASK;
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_i_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_p_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_l_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_f_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_b_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_e_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_v_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_z_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
/*
+-+-+-+-+-+-+-+-+
I: |M| PICTURE ID | (REQUIRED)
+-+-+-+-+-+-+-+-+
M: | EXTENDED PID | (RECOMMENDED)
+-+-+-+-+-+-+-+-+
*/
guint8 m = tvb_get_guint8(tvb, offset) & VP9_1_BIT_MASK;
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_m_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
if (f)
{
// Flexible mode
if (m == i)
{
if (m)
{
// Extended PID
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_pid_extended_bits, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
}
else
{
// PID
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_pid_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
}
}
else
{
// Malformated packet
}
}
else
{
// Non-flexible mode
if (m == i)
{
if (m)
{
// Extended PID
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_pg_extended_bits, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
}
else
{
// PID
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_pg_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
}
}
else
{
// Malformated packet
}
}
/*
+-+-+-+-+-+-+-+-+
L: | TID |U| SID |D| (Conditionally RECOMMENDED)
+-+-+-+-+-+-+-+-+
*/
if (l)
{
// Layer indices present
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_tid_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_u_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_sid_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_d_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
if (f)
{
// 1 octet is present for the layer indices
proto_item_set_len(vp9_descriptor_item, 4);
}
else
{
// 2 octets are present for the layer indices
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_tl0picidx_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_item_set_len(vp9_descriptor_item, 5);
offset++;
}
}
/*
+-+-+-+-+-+-+-+-+ -\
P,F: | P_DIFF |N| (Conditionally REQUIRED) - up to 3 times
+-+-+-+-+-+-+-+-+ -/
*/
if (p && f)
{
guint8 n = tvb_get_guint8(tvb, offset) & (VP9_1_BIT_MASK >> 7);
int idx = 0;
int max_p_diff = 3;
while (n && idx < max_p_diff)
{
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_p_diff_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_n_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_item_set_len(vp9_descriptor_item, 6);
offset++;
n = tvb_get_guint8(tvb, offset) & (VP9_1_BIT_MASK >> 7);
idx++;
if (n && idx == max_p_diff)
{
// Malformated packet
}
}
}
/*
+-+-+-+-+-+-+-+-+
V: | SS |
| .. |
+-+-+-+-+-+-+-+-+
*/
if (v)
{
/*
+-+-+-+-+-+-+-+-+
V: | N_S |Y|G|-|-|-|
+-+-+-+-+-+-+-+-+
*/
guint8 n_s = (tvb_get_guint8(tvb, offset) & (VP9_3_BITS_MASK)) >> 5;
guint8 y = tvb_get_guint8(tvb, offset) & (VP9_1_BIT_MASK >> 3);
guint8 g = tvb_get_guint8(tvb, offset) & (VP9_1_BIT_MASK >> 4);
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_n_s_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_y_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_g_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
/*
+-+-+-+-+-+-+-+-+ -\
Y: | WIDTH | (OPTIONAL) .
+ + .
| | (OPTIONAL) .
+-+-+-+-+-+-+-+-+ . - N_S + 1 times
| HEIGHT | (OPTIONAL) .
+ + .
| | (OPTIONAL) .
+-+-+-+-+-+-+-+-+ -/
*/
guint8 spatial_layer = 0;
while (spatial_layer < (n_s + 1))
{
if (y)
{
// TODO: Add subtree for spatial layers
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_width_bits, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_height_bits, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
}
spatial_layer++;
}
/*
+-+-+-+-+-+-+-+-+
G: | N_G | (OPTIONAL)
+-+-+-+-+-+-+-+-+
*/
if (g)
{
/*
+-+-+-+-+-+-+-+-+ -\
N_G: | TID |U| R |-|-| (OPTIONAL) .
+-+-+-+-+-+-+-+-+ -\ . - N_G times
| P_DIFF | (OPTIONAL) . - R times .
+-+-+-+-+-+-+-+-+ -/ -/
*/
proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_n_g_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
// TODO: handle N_G
}
}
return tvb_captured_length(tvb);
}
void proto_register_vp9(void)
{
static hf_register_info hf[] = {
{&hf_vp9_pld_i_bit,
{"Picture ID present", "vp9.pld.i",
FT_BOOLEAN, 8,
NULL, VP9_1_BIT_MASK,
NULL, HFILL}},
{&hf_vp9_pld_p_bit,
{"Inter-picture predicted frame", "vp9.pld.p",
FT_BOOLEAN, 8,
NULL, VP9_2_BIT_MASK,
NULL, HFILL}},
{&hf_vp9_pld_l_bit,
{"Layer indices present", "vp9.pld.l",
FT_BOOLEAN, 8,
NULL, VP9_3_BIT_MASK,
NULL, HFILL}},
{&hf_vp9_pld_f_bit,
{"Flexible mode", "vp9.pld.f",
FT_BOOLEAN, 8,
NULL, VP9_4_BIT_MASK,
NULL, HFILL}},
{&hf_vp9_pld_b_bit,
{"Start of a frame", "vp9.pld.b",
FT_BOOLEAN, 8,
NULL, VP9_5_BIT_MASK,
NULL, HFILL}},
{&hf_vp9_pld_e_bit,
{"End of a frame", "vp9.pld.e",
FT_BOOLEAN, 8,
NULL, VP9_6_BIT_MASK,
NULL, HFILL}},
{&hf_vp9_pld_v_bit,
{"Scalability structure (SS) data present", "vp9.pld.v",
FT_BOOLEAN, 8,
NULL, VP9_7_BIT_MASK,
NULL, HFILL}},
{&hf_vp9_pld_z_bit,
{"Not a reference frame for upper spatial layers", "vp9.pld.z",
FT_BOOLEAN, 8,
NULL, VP9_8_BIT_MASK,
NULL, HFILL}},
{&hf_vp9_pld_m_bit,
{"Extension flag", "vp9.pld.m",
FT_BOOLEAN, 8,
NULL, VP9_1_BIT_MASK,
NULL, HFILL}},
{&hf_vp9_pld_pid_bits,
{"Picture ID (PID)", "vp9.pld.pid",
FT_UINT8, BASE_DEC,
NULL, VP9_7_BITS_MASK >> 1,
NULL, HFILL}},
{&hf_vp9_pld_pid_extended_bits,
{"Picture ID (PID) Extended", "vp9.pld.pid_ext",
FT_UINT16, BASE_DEC,
NULL, VP9_EXTENDED_PID,
NULL, HFILL}},
{&hf_vp9_pld_pg_bits,
{"Picture Group Index (PG)", "vp9.pld.pg",
FT_UINT8, BASE_DEC,
NULL, VP9_7_BITS_MASK >> 1,
NULL, HFILL}},
{&hf_vp9_pld_pg_extended_bits,
{"Picture Group Index (PG) Extended", "vp9.pld.pg_ext",
FT_UINT16, BASE_DEC,
NULL, VP9_EXTENDED_PID,
NULL, HFILL}},
{&hf_vp9_pld_tid_bits,
{"Temporal layer ID", "vp9.pld.tid",
FT_UINT8, BASE_DEC,
NULL, VP9_3_BITS_MASK,
NULL, HFILL}},
{&hf_vp9_pld_u_bit,
{"Switching up point", "vp9.pld.u",
FT_BOOLEAN, 8,
NULL, VP9_1_BIT_MASK >> 3,
NULL, HFILL}},
{&hf_vp9_pld_sid_bits,
{"Spatial Layer ID", "vp9.pld.sid",
FT_UINT8, BASE_DEC,
NULL, VP9_3_BITS_MASK >> 4,
NULL, HFILL}},
{&hf_vp9_pld_d_bit,
{"Inter-layer dependency used", "vp9.pld.d",
FT_BOOLEAN, 8,
NULL, VP9_1_BIT_MASK >> 7,
NULL, HFILL}},
{&hf_vp9_pld_tl0picidx_bits,
{"Temporal layer zero index", "vp9.pld.tl0picidx",
FT_UINT8, BASE_DEC,
NULL, 0,
NULL, HFILL}},
{&hf_vp9_pld_p_diff_bits,
{"Reference index", "vp9.pld.p_diff",
FT_UINT8, BASE_DEC,
NULL, VP9_7_BITS_MASK,
NULL, HFILL}},
{&hf_vp9_pld_n_bit,
{"Additional reference index", "vp9.pld.n",
FT_BOOLEAN, 8,
NULL, VP9_1_BIT_MASK >> 7,
NULL, HFILL}},
{&hf_vp9_pld_n_s_bits,
{"Number of spatial layers", "vp9.pld.n_s",
FT_UINT8, BASE_DEC,
NULL, VP9_3_BITS_MASK,
NULL, HFILL}},
{&hf_vp9_pld_y_bit,
{"Spatial layer's frame resolution present", "vp9.pld.y",
FT_BOOLEAN, 8,
NULL, VP9_1_BIT_MASK >> 3,
NULL, HFILL}},
{&hf_vp9_pld_g_bit,
{"PG description flag", "vp9.pld.g",
FT_BOOLEAN, 8,
NULL, VP9_1_BIT_MASK >> 4,
NULL, HFILL}},
{&hf_vp9_pld_height_bits,
{"Height", "vp9.pld.height",
FT_UINT16, BASE_DEC,
NULL, 0,
NULL, HFILL}},
{&hf_vp9_pld_width_bits,
{"Width", "vp9.pld.width",
FT_UINT16, BASE_DEC,
NULL, 0,
NULL, HFILL}},
{&hf_vp9_pld_n_g_bits,
{"Number of pictures", "vp9.pld.n_g",
FT_UINT8, BASE_DEC,
NULL, 0,
NULL, HFILL}}};
proto_vp9 = proto_register_protocol("VP9", "VP9", "vp9");
proto_register_field_array(proto_vp9, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void proto_reg_handoff_vp9(void)
{
static dissector_handle_t vp9_handle;
vp9_handle = register_dissector("vp9", dissect_vp9, proto_vp9);
dissector_add_string("rtp_dyn_payload_type", "vp9", vp9_handle);
dissector_add_uint_range_with_preference("rtp.pt", "", vp9_handle);
}
/*
* 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:
*/
|
