/* * packet-mp4ves.c * Routines for MPEG4 dissection * Copyright 2007-2008, Anders Broman * * $Id$ * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * References: * http://www.ietf.org/rfc/rfc3016.txt?number=3016 */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include #include #include #include #include "prefs.h" /* Initialize the protocol and registered fields */ static int proto_mp4ves = -1; static int hf_mp4ves_config = -1; static int hf_mp4ves_start_code_prefix = -1; static int hf_mp4ves_start_code = -1; static int hf_mp4ves_vop_coding_type = -1; /* Initialize the subtree pointers */ static int ett_mp4ves = -1; static int ett_mp4ves_config = -1; /* The dynamic payload type which will be dissected as MP4V-ES */ static guint global_dynamic_payload_type = 0; static const range_string mp4ves_startcode_vals[] = { { 0, 0x1f, "video_object_start_code" }, { 0x20, 0x2f, "video_object_layer_start_code" }, { 0x30, 0xaf, "reserved" }, { 0xb0, 0xb0, "visual_object_sequence_start_code" }, { 0xb1, 0xb1, "visual_object_sequence_end_code" }, { 0xb2, 0xb2, "user_data_start_code" }, { 0xb3, 0xb3, "group_of_vop_start_code" }, { 0xb4, 0xb4, "video_session_error_code" }, { 0xb5, 0xb5, "visual_object_start_code" }, { 0xb6, 0xb6, "vop_start_code" }, { 0xb7, 0xb9, "reserved" }, { 0xba, 0xba, "fba_object_start_code" }, { 0xbb, 0xbb, "fba_object_plane_start_code" }, { 0xbc, 0xbc, "mesh_object_start_code" }, { 0xbd, 0xbd, "mesh_object_plane_start_code" }, { 0xbe, 0xbe, "still_texture_object_start_code" }, { 0xbf, 0xbf, "texture_spatial_layer_start_code" }, { 0xc0, 0xc0, "texture_snr_layer_start_code" }, { 0xc1, 0xc1, "texture_tile_start_code" }, { 0xc2, 0xc2, "texture_shape_layer_start_code" }, { 0xc3, 0xc3, "stuffing_start_code" }, { 0xc4, 0xc5, "reserved" }, { 0xc6, 0xcf, "System start codes" }, /* NOTE System start codes are defined in ISO/IEC 14496-1:1999 */ { 0, 0, NULL } }; static const value_string mp4ves_vop_coding_type_vals[] = { { 0, "intra-coded (I)" }, { 1, "predictive-coded (P)" }, { 2, "bidirectionally-predictive-coded (B)" }, { 3, "sprite (S)" }, { 0, NULL } }; #if 0 To be called from packet-sdp.c void dissect_mp4ves_config(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { proto_item *item; proto_tree *mp4ves_tree; int bit_offset = 0; guint32 dword; item = proto_tree_add_item(tree, hf_mp4ves_config, tvb, 0, -1, FALSE); mp4ves_tree = proto_item_add_subtree(item, ett_mp4ves_config); /* Get start code prefix */ dword = tvb_get_bits32(tvb,bit_offset, 24, FALSE); if (dword == 1){ }else{ /* No start code prefix */ return; } proto_tree_add_bits_item(tree, hf_mp4ves_start_code_prefix, tvb, bit_offset, 24, FALSE); bit_offset = bit_offset+24; /* We are byte aligned no stuffing */ dword = tvb_get_bits8(tvb,bit_offset, 8); proto_tree_add_bits_item(tree, hf_mp4ves_start_code, tvb, bit_offset, 8, FALSE); } #endif void dissect_mp4ves(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { int bit_offset = 0; proto_item *item; proto_tree *mp4ves_tree; guint32 dword; /* Make entries in Protocol column and Info column on summary display */ if (check_col(pinfo->cinfo, COL_PROTOCOL)) col_set_str(pinfo->cinfo, COL_PROTOCOL, "MP4V-ES"); if (tree) { item = proto_tree_add_item(tree, proto_mp4ves, tvb, 0, -1, FALSE); mp4ves_tree = proto_item_add_subtree(item, ett_mp4ves); /* +------+------+------+------+ (a) | RTP | VS | VO | VOL | |header|header|header|header| +------+------+------+------+ +------+------+------+------+------------+ (b) | RTP | VS | VO | VOL |Video Packet| |header|header|header|header| | +------+------+------+------+------------+ +------+-----+------------------+ (c) | RTP | GOV |Video Object Plane| |header| | | +------+-----+------------------+ +------+------+------------+ +------+------+------------+ (d) | RTP | VOP |Video Packet| | RTP | VP |Video Packet| |header|header| (1) | |header|header| (2) | +------+------+------------+ +------+------+------------+ +------+------+------------+------+------------+------+------------+ (e) | RTP | VP |Video Packet| VP |Video Packet| VP |Video Packet| |header|header| (1) |header| (2) |header| (3) | +------+------+------------+------+------------+------+------------+ +------+------+------------+ +------+------------+ (f) | RTP | VOP |VOP fragment| | RTP |VOP fragment| |header|header| (1) | |header| (2) | ___ +------+------+------------+ +------+------------+ Figure 2 - Examples of RTP packetized MPEG-4 Visual bitstream So a valid packet should start with VS - Visual Object Sequence Header GOV - Group_of_VideoObjectPlane VOP - Video Object Plane VP - Video Plane Otherwies it's a VOP fragment. visual_object_sequence_start_code: The visual_object_sequence_start_code is the bit string '000001B0' in hexadecimal. It initiates a visual session. group_of_vop_start_code: The group_of_vop_start_code is the bit string '000001B3' in hexadecimal. It identifies the beginning of a GOV header. vop_start_code: This is the bit string '000001B6' in hexadecimal. */ dword = tvb_get_bits32(tvb,bit_offset, 24, FALSE); if (dword != 1){ /* if it's not 23 zeros followed by 1 it isn't a start code */ proto_tree_add_text(tree, tvb, bit_offset>>3, -1, "Data"); return; } proto_tree_add_bits_item(tree, hf_mp4ves_start_code_prefix, tvb, bit_offset, 24, FALSE); bit_offset = bit_offset+24; dword = tvb_get_bits8(tvb,bit_offset, 8); proto_tree_add_bits_item(tree, hf_mp4ves_start_code, tvb, bit_offset, 8, FALSE); bit_offset = bit_offset+8; switch(dword){ /* vop_start_code */ case 0xb6: /* vop_coding_type 2 bits */ proto_tree_add_bits_item(tree, hf_mp4ves_vop_coding_type, tvb, bit_offset, 2, FALSE); break; default: break; } } } void proto_reg_handoff_mp4ves(void) { static dissector_handle_t mp4ves_handle; static guint dynamic_payload_type; static gboolean mp4ves_prefs_initialized = FALSE; if (!mp4ves_prefs_initialized) { mp4ves_handle = find_dissector("mp4ves"); dissector_add_string("rtp_dyn_payload_type","MP4V-ES", mp4ves_handle); mp4ves_prefs_initialized = TRUE; }else{ if ( dynamic_payload_type > 95 ) dissector_delete("rtp.pt", dynamic_payload_type, mp4ves_handle); } dynamic_payload_type = global_dynamic_payload_type; if ( dynamic_payload_type > 95 ){ dissector_add("rtp.pt", dynamic_payload_type, mp4ves_handle); } } void proto_register_mp4ves(void) { /* Setup list of header fields See Section 1.6.1 for details*/ static hf_register_info hf[] = { { &hf_mp4ves_config, { "Configuration", "mp4ves.configuration", FT_BYTES, BASE_NONE, NULL, 0x0, "Configuration", HFILL } }, { &hf_mp4ves_start_code_prefix, { "start code prefix", "mp4ves.start_code_prefix", FT_UINT32, BASE_HEX, NULL, 0x0, "start code prefix", HFILL } }, { &hf_mp4ves_start_code, { "Start code", "mp4ves.start_code", FT_UINT32, BASE_HEX, RVALS(&mp4ves_startcode_vals), 0x0, "Start code", HFILL } }, { &hf_mp4ves_vop_coding_type, { "vop_coding_type", "mp4ves.vop_coding_type", FT_UINT8, BASE_DEC, VALS(mp4ves_vop_coding_type_vals), 0x0, "Start code", HFILL } }, }; /* Setup protocol subtree array */ static gint *ett[] = { &ett_mp4ves, &ett_mp4ves_config, }; module_t *mp4ves_module; /* Register the protocol name and description */ proto_mp4ves = proto_register_protocol("MP4V-ES","MP4V-ES", "mp4v-es"); /* Required function calls to register the header fields and subtrees used */ proto_register_field_array(proto_mp4ves, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); /* Register a configuration option for port */ register_dissector("mp4ves", dissect_mp4ves, proto_mp4ves); /* Register a configuration option for port */ mp4ves_module = prefs_register_protocol(proto_mp4ves, proto_reg_handoff_mp4ves); prefs_register_uint_preference(mp4ves_module, "dynamic.payload.type", "MP4V-ES dynamic payload type", "The dynamic payload type which will be interpreted as MP4V-ES", 10, &global_dynamic_payload_type); }