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/*
* packet-mp4ves.c
* Routines for MPEG4 dissection
* Copyright 2007-2008, Anders Broman <anders.broman[at]ericsson.com>
*
* $Id$
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <glib.h>
#include <epan/packet.h>
#include <epan/proto.h>
#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 dynamic_payload_type = 0;
static guint temp_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)
{
dissector_handle_t mp4ves_handle;
static int mp4ves_prefs_initialized = FALSE;
mp4ves_handle = create_dissector_handle(dissect_mp4ves, proto_mp4ves);
if (!mp4ves_prefs_initialized) {
mp4ves_prefs_initialized = TRUE;
}else{
if ( dynamic_payload_type > 95 )
dissector_delete("rtp.pt", dynamic_payload_type, mp4ves_handle);
}
dynamic_payload_type = temp_dynamic_payload_type;
if ( dynamic_payload_type > 95 ){
dissector_add("rtp.pt", dynamic_payload_type, mp4ves_handle);
}
dissector_add_string("rtp_dyn_payload_type","MP4V-ES", 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,
&temp_dynamic_payload_type);
}
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