epan/dissectors/packet-vp9.c

   1 /* packet-vp9.c
   2  * Routines for VP9 dissection
   3  * Copyright 2023, Noan Perrot <noan.perrot@gmail.com>
   4  *
   5  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998 Gerald Combs
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-or-later
  10  */
  11
  12 /*
  13  * vp9-bitstream-specification-v0.6-20160331-draft - VP9 Bitstream & Decoding Process Specification
  14  * draft-ietf-payload-vp9-16 - RTP Payload Format for VP9 Video
  15  */
  16
  17 #include "config.h"
  18 /* Define the name for the logging domain (try to avoid collisions with existing domains) */
  19 #define WS_LOG_DOMAIN "vp9"
  20
  21 /* Global header providing a minimum base set of required macros and APIs */
  22 #include <wireshark.h>
  23
  24 #include <epan/packet.h> /* Required dissection API header */
  25 #include <epan/expert.h> /* Include only as needed */
  26 #include <epan/prefs.h>  /* Include only as needed */
  27
  28 #define STRING_SIZE 50
  29 #define VP9_1_BIT_MASK 0x80
  30 #define VP9_2_BIT_MASK 0x40
  31 #define VP9_3_BIT_MASK 0x20
  32 #define VP9_4_BIT_MASK 0x10
  33 #define VP9_5_BIT_MASK 0x08
  34 #define VP9_6_BIT_MASK 0x04
  35 #define VP9_7_BIT_MASK 0x02
  36 #define VP9_8_BIT_MASK 0x01
  37 #define VP9_2_BITS_MASK 0xC0
  38 #define VP9_3_BITS_MASK 0xE0
  39 #define VP9_7_BITS_MASK 0xFE
  40 #define VP9_8_BITS_MASK 0xFF
  41 #define VP9_16_BITS_MASK 0xFFFF
  42 #define VP9_EXTENDED_PID 0x7FFF
  43
  44 static int proto_vp9;
  45
  46 static int hf_vp9_pld_i_bit;
  47 static int hf_vp9_pld_p_bit;
  48 static int hf_vp9_pld_l_bit;
  49 static int hf_vp9_pld_f_bit;
  50 static int hf_vp9_pld_b_bit;
  51 static int hf_vp9_pld_e_bit;
  52 static int hf_vp9_pld_v_bit;
  53 static int hf_vp9_pld_z_bit;
  54 static int hf_vp9_pld_u_bit;
  55 static int hf_vp9_pld_m_bit;
  56 static int hf_vp9_pld_d_bit;
  57 static int hf_vp9_pld_n_bit;
  58 static int hf_vp9_pld_y_bit;
  59 static int hf_vp9_pld_g_bit;
  60 static int hf_vp9_pld_pg_bits;
  61 static int hf_vp9_pld_n_s_bits;
  62 static int hf_vp9_pld_n_g_bits;
  63 static int hf_vp9_pld_sid_bits;
  64 static int hf_vp9_pld_pid_bits;
  65 static int hf_vp9_pld_tid_bits;
  66 static int hf_vp9_pld_width_bits;
  67 static int hf_vp9_pld_height_bits;
  68 static int hf_vp9_pld_n_s_numbers;
  69 static int hf_vp9_pld_p_diff_bits;
  70 static int hf_vp9_pld_tl0picidx_bits;
  71 static int hf_vp9_pld_pg_extended_bits;
  72 static int hf_vp9_pld_pid_extended_bits;
  73
  74 static int ett_vp9;
  75 static int ett_vp9_descriptor;
  76
  77 static int *ett[] = {
  78     &ett_vp9,
  79     &ett_vp9_descriptor
  80 };
  81
  82 static int
  83 dissect_vp9(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree _U_, void *data _U_)
  84 {
  85     col_set_str(pinfo->cinfo, COL_PROTOCOL, "VP9");
  86
  87     proto_item *vp9_item = proto_tree_add_item(tree, proto_vp9, tvb, 0, -1, ENC_NA);
  88     proto_tree *vp9_tree = proto_item_add_subtree(vp9_item, ett_vp9);
  89
  90     proto_item *vp9_descriptor_item;
  91     proto_tree *vp9_descriptor_tree = proto_tree_add_subtree(vp9_tree, tvb, 0, 1, ett_vp9_descriptor, &vp9_descriptor_item, "Payload Descriptor");
  92
  93     int offset = 0;
  94
  95     /*
  96           0 1 2 3 4 5 6 7
  97          +-+-+-+-+-+-+-+-+
  98          |I|P|L|F|B|E|V|Z| (REQUIRED)
  99          +-+-+-+-+-+-+-+-+
 100     */
 101     uint8_t i = tvb_get_uint8(tvb, offset) & VP9_1_BIT_MASK;
 102     uint8_t p = tvb_get_uint8(tvb, offset) & VP9_2_BIT_MASK;
 103     uint8_t l = tvb_get_uint8(tvb, offset) & VP9_3_BIT_MASK;
 104     uint8_t f = tvb_get_uint8(tvb, offset) & VP9_4_BIT_MASK;
 105     uint8_t v = tvb_get_uint8(tvb, offset) & VP9_7_BIT_MASK;
 106     proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_i_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
 107     proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_p_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
 108     proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_l_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
 109     proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_f_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
 110     proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_b_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
 111     proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_e_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
 112     proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_v_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
 113     proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_z_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
 114
 115     offset++;
 116
 117     /*
 118          +-+-+-+-+-+-+-+-+
 119     I:   |M| PICTURE ID  | (REQUIRED)
 120          +-+-+-+-+-+-+-+-+
 121     M:   | EXTENDED PID  | (RECOMMENDED)
 122          +-+-+-+-+-+-+-+-+
 123     */
 124     uint8_t m = tvb_get_uint8(tvb, offset) & VP9_1_BIT_MASK;
 125     proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_m_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
 126     if (f)
 127     {
 128         //  Flexible mode
 129         if (m == i)
 130         {
 131             if (m)
 132             {
 133                 //  Extended PID
 134                 proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_pid_extended_bits, tvb, offset, 2, ENC_BIG_ENDIAN);
 135                 offset += 2;
 136             }
 137             else
 138             {
 139                 //  PID
 140                 proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_pid_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
 141                 offset++;
 142             }
 143         }
 144         else
 145         {
 146             //  Malformed packet
 147         }
 148     }
 149     else
 150     {
 151         //  Non-flexible mode
 152         if (m == i)
 153         {
 154             if (m)
 155             {
 156                 //  Extended PID
 157                 proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_pg_extended_bits, tvb, offset, 2, ENC_BIG_ENDIAN);
 158                 offset += 2;
 159             }
 160             else
 161             {
 162                 //  PID
 163                 proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_pg_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
 164                 offset++;
 165             }
 166         }
 167         else
 168         {
 169             //  Malformed packet
 170         }
 171     }
 172
 173     /*
 174          +-+-+-+-+-+-+-+-+
 175     L:   | TID |U| SID |D| (Conditionally RECOMMENDED)
 176          +-+-+-+-+-+-+-+-+
 177     */
 178     if (l)
 179     {
 180         //  Layer indices present
 181         proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_tid_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
 182         proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_u_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
 183         proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_sid_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
 184         proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_d_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
 185         offset++;
 186
 187         if (f)
 188         {
 189             //  1 octet is present for the layer indices
 190             proto_item_set_len(vp9_descriptor_item, 4);
 191         }
 192         else
 193         {
 194             //  2 octets are present for the layer indices
 195             proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_tl0picidx_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
 196             proto_item_set_len(vp9_descriptor_item, 5);
 197             offset++;
 198         }
 199     }
 200
 201     /*
 202           +-+-+-+-+-+-+-+-+                             -\
 203      P,F: | P_DIFF      |N| (Conditionally REQUIRED)    - up to 3 times
 204           +-+-+-+-+-+-+-+-+                             -/
 205     */
 206     if (p && f)
 207     {
 208         uint8_t n = tvb_get_uint8(tvb, offset) & (VP9_1_BIT_MASK >> 7);
 209         int idx = 0;
 210         int max_p_diff = 3;
 211         while (n && idx < max_p_diff)
 212         {
 213             proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_p_diff_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
 214             proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_n_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
 215             proto_item_set_len(vp9_descriptor_item, 6);
 216             offset++;
 217             n = tvb_get_uint8(tvb, offset) & (VP9_1_BIT_MASK >> 7);
 218             idx++;
 219             if (n && idx == max_p_diff)
 220             {
 221                 //  Malformed packet
 222             }
 223         }
 224     }
 225
 226     /*
 227            +-+-+-+-+-+-+-+-+
 228       V:   | SS            |
 229            | ..            |
 230            +-+-+-+-+-+-+-+-+
 231     */
 232     if (v)
 233     {
 234         /*
 235              +-+-+-+-+-+-+-+-+
 236         V:   | N_S |Y|G|-|-|-|
 237              +-+-+-+-+-+-+-+-+
 238         */
 239         proto_item* n_s_numbers_field;
 240         uint8_t n_s = (tvb_get_uint8(tvb, offset) & (VP9_3_BITS_MASK)) >> 5;
 241         uint8_t y = tvb_get_uint8(tvb, offset) & (VP9_1_BIT_MASK >> 3);
 242         uint8_t g = tvb_get_uint8(tvb, offset) & (VP9_1_BIT_MASK >> 4);
 243         uint8_t number_of_spatial_layers = n_s + 1;
 244
 245         proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_n_s_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
 246         n_s_numbers_field = proto_tree_add_uint(vp9_descriptor_tree, hf_vp9_pld_n_s_numbers, tvb, offset, 1, number_of_spatial_layers);
 247         proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_y_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
 248         proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_g_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
 249         proto_item_set_generated(n_s_numbers_field);
 250
 251         offset++;
 252
 253         /*
 254              +-+-+-+-+-+-+-+-+              -\
 255         Y:   |     WIDTH     | (OPTIONAL)    .
 256              +               +               .
 257              |               | (OPTIONAL)    .
 258              +-+-+-+-+-+-+-+-+               . - N_S + 1 times
 259              |     HEIGHT    | (OPTIONAL)    .
 260              +               +               .
 261              |               | (OPTIONAL)    .
 262              +-+-+-+-+-+-+-+-+              -/
 263         */
 264         uint8_t spatial_layer = 0;
 265         while (spatial_layer < number_of_spatial_layers)
 266         {
 267             if (y)
 268             {
 269                 //  TODO: Add subtree for spatial layers
 270                 proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_width_bits, tvb, offset, 2, ENC_BIG_ENDIAN);
 271                 offset += 2;
 272                 proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_height_bits, tvb, offset, 2, ENC_BIG_ENDIAN);
 273                 offset += 2;
 274             }
 275             spatial_layer++;
 276         }
 277
 278         /*
 279              +-+-+-+-+-+-+-+-+
 280         G:   |      N_G      | (OPTIONAL)
 281              +-+-+-+-+-+-+-+-+
 282         */
 283         if (g)
 284         {
 285             /*
 286                      +-+-+-+-+-+-+-+-+                            -\
 287             N_G:     | TID |U| R |-|-| (OPTIONAL)                 .
 288                      +-+-+-+-+-+-+-+-+              -\            . - N_G times
 289                      |    P_DIFF     | (OPTIONAL)    . - R times  .
 290                      +-+-+-+-+-+-+-+-+              -/            -/
 291             */
 292             proto_tree_add_item(vp9_descriptor_tree, hf_vp9_pld_n_g_bits, tvb, offset, 1, ENC_BIG_ENDIAN);
 293             offset++;
 294             //  TODO: handle N_G
 295         }
 296     }
 297
 298     return tvb_captured_length(tvb);
 299 }
 300
 301 void proto_register_vp9(void)
 302 {
 303     static hf_register_info hf[] = {
 304         {&hf_vp9_pld_i_bit,
 305          {"Picture ID present (I)", "vp9.pld.i",
 306           FT_BOOLEAN, 8,
 307           NULL, VP9_1_BIT_MASK,
 308           NULL, HFILL}},
 309         {&hf_vp9_pld_p_bit,
 310          {"Inter-picture predicted frame (P)", "vp9.pld.p",
 311           FT_BOOLEAN, 8,
 312           NULL, VP9_2_BIT_MASK,
 313           NULL, HFILL}},
 314         {&hf_vp9_pld_l_bit,
 315          {"Layer indices present (L)", "vp9.pld.l",
 316           FT_BOOLEAN, 8,
 317           NULL, VP9_3_BIT_MASK,
 318           NULL, HFILL}},
 319         {&hf_vp9_pld_f_bit,
 320          {"Flexible mode (F)", "vp9.pld.f",
 321           FT_BOOLEAN, 8,
 322           NULL, VP9_4_BIT_MASK,
 323           NULL, HFILL}},
 324         {&hf_vp9_pld_b_bit,
 325          {"Start of a frame (B)", "vp9.pld.b",
 326           FT_BOOLEAN, 8,
 327           NULL, VP9_5_BIT_MASK,
 328           NULL, HFILL}},
 329         {&hf_vp9_pld_e_bit,
 330          {"End of a frame (E)", "vp9.pld.e",
 331           FT_BOOLEAN, 8,
 332           NULL, VP9_6_BIT_MASK,
 333           NULL, HFILL}},
 334         {&hf_vp9_pld_v_bit,
 335          {"Scalability structure (SS) data present (V)", "vp9.pld.v",
 336           FT_BOOLEAN, 8,
 337           NULL, VP9_7_BIT_MASK,
 338           NULL, HFILL}},
 339         {&hf_vp9_pld_z_bit,
 340          {"Not a reference frame for upper spatial layers (Z)", "vp9.pld.z",
 341           FT_BOOLEAN, 8,
 342           NULL, VP9_8_BIT_MASK,
 343           NULL, HFILL}},
 344         {&hf_vp9_pld_m_bit,
 345          {"Extension flag (M)", "vp9.pld.m",
 346           FT_BOOLEAN, 8,
 347           NULL, VP9_1_BIT_MASK,
 348           NULL, HFILL}},
 349         {&hf_vp9_pld_pid_bits,
 350          {"Picture ID (PID)", "vp9.pld.pid",
 351           FT_UINT8, BASE_DEC,
 352           NULL, VP9_7_BITS_MASK >> 1,
 353           NULL, HFILL}},
 354         {&hf_vp9_pld_pid_extended_bits,
 355          {"Picture ID (PID) Extended", "vp9.pld.pid_ext",
 356           FT_UINT16, BASE_DEC,
 357           NULL, VP9_EXTENDED_PID,
 358           NULL, HFILL}},
 359         {&hf_vp9_pld_pg_bits,
 360          {"Picture Group Index (PG)", "vp9.pld.pg",
 361           FT_UINT8, BASE_DEC,
 362           NULL, VP9_7_BITS_MASK >> 1,
 363           NULL, HFILL}},
 364         {&hf_vp9_pld_pg_extended_bits,
 365          {"Picture Group Index (PG) Extended", "vp9.pld.pg_ext",
 366           FT_UINT16, BASE_DEC,
 367           NULL, VP9_EXTENDED_PID,
 368           NULL, HFILL}},
 369         {&hf_vp9_pld_tid_bits,
 370          {"Temporal layer ID", "vp9.pld.tid",
 371           FT_UINT8, BASE_DEC,
 372           NULL, VP9_3_BITS_MASK,
 373           NULL, HFILL}},
 374         {&hf_vp9_pld_u_bit,
 375          {"Switching up point (U)", "vp9.pld.u",
 376           FT_BOOLEAN, 8,
 377           NULL, VP9_1_BIT_MASK >> 3,
 378           NULL, HFILL}},
 379         {&hf_vp9_pld_sid_bits,
 380          {"Spatial Layer ID", "vp9.pld.sid",
 381           FT_UINT8, BASE_DEC,
 382           NULL, VP9_3_BITS_MASK >> 4,
 383           NULL, HFILL}},
 384         {&hf_vp9_pld_d_bit,
 385          {"Inter-layer dependency used (D)", "vp9.pld.d",
 386           FT_BOOLEAN, 8,
 387           NULL, VP9_1_BIT_MASK >> 7,
 388           NULL, HFILL}},
 389         {&hf_vp9_pld_tl0picidx_bits,
 390          {"Temporal layer zero index", "vp9.pld.tl0picidx",
 391           FT_UINT8, BASE_DEC,
 392           NULL, 0,
 393           NULL, HFILL}},
 394         {&hf_vp9_pld_p_diff_bits,
 395          {"Reference index (P_DIFF)", "vp9.pld.p_diff",
 396           FT_UINT8, BASE_DEC,
 397           NULL, VP9_7_BITS_MASK,
 398           NULL, HFILL}},
 399         {&hf_vp9_pld_n_bit,
 400          {"Additional reference index (N)", "vp9.pld.n",
 401           FT_BOOLEAN, 8,
 402           NULL, VP9_1_BIT_MASK >> 7,
 403           NULL, HFILL}},
 404         {&hf_vp9_pld_n_s_bits,
 405          {"Spatial layers minus 1 (N_S)", "vp9.pld.n_s",
 406           FT_UINT8, BASE_DEC,
 407           NULL, VP9_3_BITS_MASK,
 408           NULL, HFILL}},
 409         {&hf_vp9_pld_n_s_numbers,
 410          {"Number of spatial layers", "vp9.pld.spatial_layers_number",
 411           FT_UINT8, BASE_DEC,
 412           NULL, 0,
 413           NULL, HFILL}},
 414         {&hf_vp9_pld_y_bit,
 415          {"Spatial layer's frame resolution present (Y)", "vp9.pld.y",
 416           FT_BOOLEAN, 8,
 417           NULL, VP9_1_BIT_MASK >> 3,
 418           NULL, HFILL}},
 419         {&hf_vp9_pld_g_bit,
 420          {"PG description flag (G)", "vp9.pld.g",
 421           FT_BOOLEAN, 8,
 422           NULL, VP9_1_BIT_MASK >> 4,
 423           NULL, HFILL}},
 424         {&hf_vp9_pld_height_bits,
 425          {"Height", "vp9.pld.height",
 426           FT_UINT16, BASE_DEC,
 427           NULL, 0,
 428           NULL, HFILL}},
 429         {&hf_vp9_pld_width_bits,
 430          {"Width", "vp9.pld.width",
 431           FT_UINT16, BASE_DEC,
 432           NULL, 0,
 433           NULL, HFILL}},
 434         {&hf_vp9_pld_n_g_bits,
 435          {"Number of pictures (N_G)", "vp9.pld.n_g",
 436           FT_UINT8, BASE_DEC,
 437           NULL, 0,
 438           NULL, HFILL}}};
 439
 440     proto_vp9 = proto_register_protocol("VP9", "VP9", "vp9");
 441
 442     proto_register_field_array(proto_vp9, hf, array_length(hf));
 443     proto_register_subtree_array(ett, array_length(ett));
 444 }
 445
 446 void proto_reg_handoff_vp9(void)
 447 {
 448     static dissector_handle_t vp9_handle;
 449
 450     vp9_handle = register_dissector("vp9", dissect_vp9, proto_vp9);
 451
 452     dissector_add_string("rtp_dyn_payload_type", "vp9", vp9_handle);
 453     dissector_add_uint_range_with_preference("rtp.pt", "", vp9_handle);
 454 }
 455
 456 /*
 457  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 458  *
 459  * Local variables:
 460  * c-basic-offset: 4
 461  * tab-width: 8
 462  * indent-tabs-mode: nil
 463  * End:
 464  *
 465  * vi: set shiftwidth=4 tabstop=8 expandtab:
 466  * :indentSize=4:tabSize=8:noTabs=true:
 467  */