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authorGuy Harris <guy@alum.mit.edu>2000-10-19 06:45:11 +0000
committerGuy Harris <guy@alum.mit.edu>2000-10-19 06:45:11 +0000
commit3f8b7cd0fc93040f23b1d1b0e061dc1097321f4e (patch)
treeb9eea74fb6b18aeb12b57161706786110421caa1 /packet-h261.c
parent9de17c39f5e6828c6631af911d114f935b0feb4d (diff)
Andreas Sikkema's new H.261 and TPKT dissectors, replacement RTCP and
RTP dissectors, and changes to the Q.931 dissector for use with H.323. svn path=/trunk/; revision=2511
Diffstat (limited to 'packet-h261.c')
-rw-r--r--packet-h261.c262
1 files changed, 262 insertions, 0 deletions
diff --git a/packet-h261.c b/packet-h261.c
new file mode 100644
index 0000000000..8bcbde1291
--- /dev/null
+++ b/packet-h261.c
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+/* packet-h261.c
+ *
+ * Routines for ITU-T Recommendation H.261 dissection
+ *
+ * Copyright 2000, Philips Electronics N.V.
+ * Andreas Sikkema <andreas.sikkema@philips.com>
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@zing.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.
+ */
+
+/*
+ * This dissector tries to dissect the H261 protocol according to Annex C
+ * of ITU-T Recommendation H.225.0 (02/98)
+ *
+ * This dissector is called by the RTP dissector
+ */
+
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <glib.h>
+#include "packet.h"
+
+#ifdef HAVE_SYS_TYPES_H
+# include <sys/types.h>
+#endif
+
+#ifdef HAVE_NETINET_IN_H
+# include <netinet/in.h>
+#endif
+
+#include <stdio.h>
+#include <string.h>
+
+#include "packet-h261.h"
+
+/* H261 header fields */
+static int proto_h261 = -1;
+static int hf_h261_sbit = -1;
+static int hf_h261_ebit = -1;
+static int hf_h261_ibit = -1;
+static int hf_h261_vbit = -1;
+static int hf_h261_gobn = -1;
+static int hf_h261_mbap = -1;
+static int hf_h261_quant = -1;
+static int hf_h261_hmvd = -1; /* Mislabeled in a figure in section C.3.1 as HMDV */
+static int hf_h261_vmvd = -1;
+static int hf_h261_data = -1;
+
+/* H261 fields defining a sub tree */
+static gint ett_h261 = -1;
+
+void
+dissect_h261( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
+{
+ proto_item *ti = NULL;
+ proto_tree *h261_tree = NULL;
+ unsigned int offset = 0;
+
+ if ( check_col( pinfo->fd, COL_PROTOCOL ) ) {
+ col_add_str( pinfo->fd, COL_PROTOCOL, "H261" );
+ }
+
+ if ( check_col( pinfo->fd, COL_INFO) ) {
+ col_add_str( pinfo->fd, COL_INFO, "H.261 message");
+ }
+
+ if ( tree ) {
+ /* Using fd->pkt_len here instead of END_OF_FRAME. This variable is changed in dissect_rtp()! */
+ ti = proto_tree_add_item( tree, proto_h261, tvb, offset, tvb_length( tvb ), FALSE );
+ h261_tree = proto_item_add_subtree( ti, ett_h261 );
+ /* SBIT 1st octet, 3 bits */
+ proto_tree_add_uint( h261_tree, hf_h261_sbit, tvb, offset, 1, tvb_get_guint8( tvb, offset ) >> 5 );
+ /* EBIT 1st octet, 3 bits */
+ proto_tree_add_item( h261_tree, hf_h261_ebit, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) << 3 ) >> 5 );
+ /* I flag, 1 bit */
+ proto_tree_add_boolean( h261_tree, hf_h261_ibit, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 2 );
+ /* V flag, 1 bit */
+ proto_tree_add_boolean( h261_tree, hf_h261_vbit, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 1 );
+ offset++;
+
+ /* GOBN 2nd octet, 4 bits */
+ proto_tree_add_uint( h261_tree, hf_h261_gobn, tvb, offset, 1, tvb_get_guint8( tvb, offset ) >> 4 );
+ /* MBAP 2nd octet, 4 bits, 3rd octet 1 bit */
+ proto_tree_add_uint( h261_tree, hf_h261_mbap, tvb, offset, 1,
+ ( tvb_get_guint8( tvb, offset ) & 15 )
+ + ( tvb_get_guint8( tvb, offset + 1 ) >> 7 ) );
+ offset++;
+
+ /* QUANT 3rd octet, 5 bits (starting at bit 2!) */
+ proto_tree_add_uint( h261_tree, hf_h261_mbap, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 124 );
+ /* HMDV 3rd octet 2 bits, 4th octet 3 bits */
+ proto_tree_add_uint( h261_tree, hf_h261_mbap, tvb, offset, 1,
+ ( ( tvb_get_guint8( tvb, offset ) << 4) >> 4 )
+ + ( tvb_get_guint8( tvb, offset ) >> 5 ) );
+ offset++;
+
+ /* VMVD 4th octet, last 5 bits */
+ proto_tree_add_uint( h261_tree, hf_h261_mbap, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 31 );
+ offset++;
+
+ /* The rest of the packet is the H.261 stream */
+ proto_tree_add_bytes( h261_tree, hf_h261_data, tvb, offset, tvb_length_remaining( tvb, offset ), tvb_get_ptr( tvb, offset, tvb_length_remaining( tvb, offset ) ) );
+ }
+}
+
+void
+proto_register_h261(void)
+{
+ static hf_register_info hf[] =
+ {
+ {
+ &hf_h261_sbit,
+ {
+ "Start bit position",
+ "h261.sbit",
+ FT_UINT8,
+ BASE_DEC,
+ NULL,
+ 0x0,
+ ""
+ }
+ },
+ {
+ &hf_h261_ebit,
+ {
+ "End bit position",
+ "h261.ebit",
+ FT_UINT8,
+ BASE_DEC,
+ NULL,
+ 0x0,
+ ""
+ }
+ },
+ {
+ &hf_h261_ibit,
+ {
+ "Intra frame encoded data flag",
+ "h261.i",
+ FT_BOOLEAN,
+ BASE_NONE,
+ NULL,
+ 0x0,
+ ""
+ }
+ },
+ {
+ &hf_h261_vbit,
+ {
+ "Motion vector flag",
+ "h261.v",
+ FT_BOOLEAN,
+ BASE_NONE,
+ NULL,
+ 0x0,
+ ""
+ }
+ },
+ {
+ &hf_h261_gobn,
+ {
+ "GOB Number",
+ "h261.gobn",
+ FT_UINT8,
+ BASE_DEC,
+ NULL,
+ 0x0,
+ ""
+ }
+ },
+ {
+ &hf_h261_mbap,
+ {
+ "Macroblock address predictor",
+ "h261.mbap",
+ FT_UINT8,
+ BASE_DEC,
+ NULL,
+ 0x0,
+ ""
+ }
+ },
+ {
+ &hf_h261_quant,
+ {
+ "Quantizer",
+ "h261.quant",
+ FT_UINT8,
+ BASE_DEC,
+ NULL,
+ 0x0,
+ ""
+ }
+ },
+ {
+ &hf_h261_hmvd,
+ {
+ "Horizontal motion vctor data",
+ "h261.hmvd",
+ FT_UINT8,
+ BASE_DEC,
+ NULL,
+ 0x0,
+ ""
+ }
+ },
+ {
+ &hf_h261_vmvd,
+ {
+ "Vertical motion vector data",
+ "h261.vmvd",
+ FT_UINT8,
+ BASE_DEC,
+ NULL,
+ 0x0,
+ ""
+ }
+ },
+ {
+ &hf_h261_data,
+ {
+ "H.261 stream",
+ "h261.stream",
+ FT_BYTES,
+ BASE_NONE,
+ NULL,
+ 0x0,
+ ""
+ }
+ },
+};
+
+ static gint *ett[] =
+ {
+ &ett_h261,
+ };
+
+
+ proto_h261 = proto_register_protocol("ITU-T Recommendation H.261", "h261");
+ proto_register_field_array(proto_h261, hf, array_length(hf));
+ proto_register_subtree_array(ett, array_length(ett));
+}