wireshark/epan/dissectors/packet-mpeg1.c

/* packet-mpeg1.c
 *
 * Routines for RFC 2250 MPEG-1 dissection
 *
 * Copyright 2001,
 * Francisco Javier Cabello Torres, <fjcabello@vtools.es>
 *
 * 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 MPEG-1 video streams.
 */


#include "config.h"

#include <epan/packet.h>

#include <epan/rtp_pt.h>

void proto_register_mpeg1(void);
void proto_reg_handoff_mpeg1(void);

static dissector_handle_t mpeg1_handle;

/* MPEG1 header fields             */

static int proto_mpg          = -1;

static int hf_rtp_mpg_mbz     = -1;
static int hf_rtp_mpg_T       = -1;
static int hf_rtp_mpg_tr      = -1;
static int hf_rtp_mpg_an      = -1;
static int hf_rtp_mpg_n       = -1;
static int hf_rtp_mpg_s       = -1;
static int hf_rtp_mpg_b       = -1;
static int hf_rtp_mpg_e       = -1;
static int hf_rtp_mpg_p       = -1;


static int hf_rtp_mpg_fbv     = -1;
static int hf_rtp_mpg_bfc     = -1;
static int hf_rtp_mpg_ffv     = -1;
static int hf_rtp_mpg_ffc     = -1;
static int hf_rtp_mpg_data    = -1;


/* MPEG-1 fields defining a sub tree */
static gint ett_mpg           = -1;

static const value_string rtp_mpg_picture_types_vals[] =
{
	{ 0, "Forbidden" },
	{ 1, "I-Picture" },
	{ 2, "P-Picture" },
	{ 3, "B-Picture" },
	{ 4, "D-Picture" },
	{ 5, "reserved" },
	{ 6, "reserved" },
	{ 7, "reserved" },
	{ 0, NULL },
};

static int
dissect_mpeg1( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_ )
{
	proto_item *ti;
	proto_tree *mpg_tree;
	unsigned int offset       = 0;

	static int * const mpg_fields1[] = {
		&hf_rtp_mpg_mbz,
		&hf_rtp_mpg_T,
		&hf_rtp_mpg_tr,
		NULL
	};
	static int * const mpg_fields2[] = {
		&hf_rtp_mpg_an,
		&hf_rtp_mpg_n,
		&hf_rtp_mpg_s,
		&hf_rtp_mpg_b,
		&hf_rtp_mpg_e,
		&hf_rtp_mpg_p,
		NULL
	};
	static int * const mpg_fields3[] = {
		&hf_rtp_mpg_fbv,
		&hf_rtp_mpg_bfc,
		&hf_rtp_mpg_ffv,
		&hf_rtp_mpg_ffc,
		NULL
	};

	col_set_str(pinfo->cinfo, COL_PROTOCOL, "MPEG-1");
	col_set_str(pinfo->cinfo, COL_INFO, "MPEG-1 message");

	/* Get MPEG-1  fields */

	ti = proto_tree_add_item( tree, proto_mpg, tvb, offset, -1, ENC_NA );
	mpg_tree = proto_item_add_subtree( ti, ett_mpg );

	proto_tree_add_bitmask_list(mpg_tree, tvb, offset, 2, mpg_fields1, ENC_BIG_ENDIAN);
	offset += 2;

	proto_tree_add_bitmask_list(mpg_tree, tvb, offset, 2, mpg_fields2, ENC_BIG_ENDIAN);
	offset += 1;

	proto_tree_add_bitmask_list(mpg_tree, tvb, offset, 1, mpg_fields3, ENC_NA);
	offset += 1;

	/* The rest of the packet is the MPEG-1 stream */
	proto_tree_add_item( mpg_tree, hf_rtp_mpg_data, tvb, offset, -1, ENC_NA );
	return tvb_captured_length(tvb);
}

void
proto_register_mpeg1(void)
{
	static hf_register_info hf[] =
	{
		{
			&hf_rtp_mpg_mbz,
			{
				"MBZ",
				"rtp.payload_mpeg_mbz",
				FT_UINT16,
				BASE_DEC,
				NULL,
				0xF800,
				NULL, HFILL
			}
		},
		{
			&hf_rtp_mpg_T,
			{
				"T",
				"rtp.payload_mpeg_T",
				FT_UINT16,
				BASE_DEC,
				NULL,
				0x0400,
				NULL, HFILL
			}
		},
		{
			&hf_rtp_mpg_tr,
			{
				"Temporal Reference",
				"rtp.payload_mpeg_tr",
				FT_UINT16,
				BASE_DEC,
				NULL,
				0x03FF,
				NULL, HFILL
			}
		},
		{
			&hf_rtp_mpg_an,
			{
				"AN",
				"rtp.payload_mpeg_an",
				FT_UINT16,
				BASE_DEC,
				NULL,
				0x80,
				NULL, HFILL
			}
		},

		{
			&hf_rtp_mpg_n,
			{
				"New Picture Header",
				"rtp.payload_mpeg_n",
				FT_UINT16,
				BASE_DEC,
				NULL,
				0x40,
				NULL, HFILL
			}
		},

		{
			&hf_rtp_mpg_s,
			{
				"Sequence Header",
				"rtp.payload_mpeg_s",
				FT_BOOLEAN,
				16,
				NULL,
				0x0020,
				NULL, HFILL
			}
		},

		{
			&hf_rtp_mpg_b,
			{
				"Beginning-of-slice",
				"rtp.payload_mpeg_b",
				FT_BOOLEAN,
				16,
				NULL,
				0x0010,
				NULL, HFILL
			}
		},

		{
			&hf_rtp_mpg_e,
			{
				"End-of-slice",
				"rtp.payload_mpeg_e",
				FT_BOOLEAN,
				16,
				NULL,
				0x0008,
				NULL, HFILL
			}
		},

		{
			&hf_rtp_mpg_p,
			{
				"Picture type",
				"rtp.payload_mpeg_p",
				FT_UINT16,
				BASE_DEC,
				VALS(rtp_mpg_picture_types_vals),
				0x07,
				NULL, HFILL
			}
		},

		{
			&hf_rtp_mpg_fbv,
			{
				"FBV",
				"rtp.payload_mpeg_fbv",
				FT_UINT16,
				BASE_DEC,
				NULL,
				0x80,
				NULL, HFILL
			}
		},

		{
			&hf_rtp_mpg_bfc,
			{
				"BFC",
				"rtp.payload_mpeg_bfc",
				FT_UINT16,
				BASE_DEC,
				NULL,
				0x70,
				NULL, HFILL
			}
		},
		{
			&hf_rtp_mpg_ffv,
			{
				"FFV",
				"rtp.payload_mpeg_ffv",
				FT_UINT16,
				BASE_DEC,
				NULL,
				0x08,
				NULL, HFILL
			}
		},

		{
			&hf_rtp_mpg_ffc,
			{
				"FFC",
				"rtp.payload_mpeg_ffc",
				FT_UINT16,
				BASE_DEC,
				NULL,
				0x07,
				NULL, HFILL
			}
		},
		{
			&hf_rtp_mpg_data,
			{
				"MPEG-1 stream",
				"mpeg1.stream",
				FT_BYTES,
				BASE_NONE,
				NULL,
				0x0,
				NULL, HFILL
			}
		},

	};

	static gint *ett[] =
	{
		&ett_mpg,
	};


	proto_mpg = proto_register_protocol("RFC 2250 MPEG1","MPEG1","mpeg1");
	mpeg1_handle = register_dissector("mpeg1", dissect_mpeg1, proto_mpg);
	proto_register_field_array(proto_mpg, hf, array_length(hf));
	proto_register_subtree_array(ett, array_length(ett));
}

void
proto_reg_handoff_mpeg1(void)
{
	dissector_add_uint("rtp.pt", PT_MPV, mpeg1_handle);
}

/*
 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 8
 * tab-width: 8
 * indent-tabs-mode: t
 * End:
 *
 * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 * :indentSize=8:tabSize=8:noTabs=false:
 */