VP8 RTP dissector

Change-Id: Ic21d13bf8ca77ff37c2d2d229c4e8c9d8f053677
Reviewed-on: https://code.wireshark.org/review/124
Reviewed-by: Evan Huus <eapache@gmail.com>
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>

3 files changed, 615 insertions, 0 deletions

diff --git a/epan/CMakeLists.txt b/epan/CMakeLists.txt
index 06af1686d1..33c2723533 100644
--- a/epan/CMakeLists.txt
+++ b/epan/CMakeLists.txt
@@ -1288,6 +1288,7 @@ set(DISSECTOR_SRC
 	dissectors/packet-vmlab.c
 	dissectors/packet-vnc.c
 	dissectors/packet-vntag.c
+	dissectors/packet-vp8.c
 	dissectors/packet-vrrp.c
 	dissectors/packet-vrt.c
 	dissectors/packet-vssmonitoring.c
diff --git a/epan/dissectors/Makefile.common b/epan/dissectors/Makefile.common
index 020ffeec2b..0f39f91a48 100644
--- a/epan/dissectors/Makefile.common
+++ b/epan/dissectors/Makefile.common
@@ -1207,6 +1207,7 @@ DISSECTOR_SRC = \
 	packet-vmlab.c		\
 	packet-vnc.c		\
 	packet-vntag.c		\
+	packet-vp8.c		\
 	packet-vrrp.c		\
 	packet-vrt.c        \
 	packet-vssmonitoring.c	\
diff --git a/epan/dissectors/packet-vp8.c b/epan/dissectors/packet-vp8.c
new file mode 100644
index 0000000000..64ecba94ad
--- /dev/null
+++ b/epan/dissectors/packet-vp8.c
@@ -0,0 +1,613 @@
+/* packet-vp8.c
+ * Routines for VP8 dissection
+ * Copyright 2014, Owen Williams williams.owen@gmail.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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+
+#include <epan/packet.h>
+#include <epan/prefs.h>
+#include <epan/expert.h>
+
+void proto_reg_handoff_vp8(void);
+void proto_register_vp8(void);
+
+#define BIT_1_MASK 0x80
+#define BIT_2_MASK 0x40
+#define BIT_3_MASK 0x20
+#define BIT_4_MASK 0x10
+#define BIT_5_MASK 0x08
+#define BIT_6_MASK 0x04
+#define BIT_7_MASK 0x02
+#define BIT_8_MASK 0x01
+#define BIT_123_MASK 0xE0
+#define BIT_234_MASK 0x70
+#define BIT_5678_MASK 0x0F
+#define BIT_567_MASK 0x0E
+#define BIT_45678_MASK 0x1F
+#define BIT_12_MASK 0xC0
+#define BIT_NO_MASK 0xFF
+#define BIT_2BYTE_NO_MASK 0xFFFF
+#define BIT_3BYTE_NO_MASK 0xFFFFFF
+#define BIT_EXT_PICTURE_MASK 0x7FFF
+#define BIT_PARTITION_SIZE_MASK 0xE0FFFF
+
+static range_t *temp_dynamic_payload_type_range = NULL;
+
+static dissector_handle_t vp8_handle;
+
+/* Initialize the protocol and registered fields */
+static int proto_vp8 = -1;
+static int hf_vp8_pld_x_bit = -1;
+static int hf_vp8_pld_r_bit = -1;
+static int hf_vp8_pld_n_bit = -1;
+static int hf_vp8_pld_s_bit = -1;
+static int hf_vp8_pld_part_id = -1;
+static int hf_vp8_pld_i_bit = -1;
+static int hf_vp8_pld_l_bit = -1;
+static int hf_vp8_pld_t_bit = -1;
+static int hf_vp8_pld_k_bit = -1;
+static int hf_vp8_pld_rsv_a = -1;
+static int hf_vp8_pld_picture_id = -1;
+static int hf_vp8_pld_extended_picture_id = -1;
+static int hf_vp8_pld_tl0picidx = -1;
+static int hf_vp8_pld_tid = -1;
+static int hf_vp8_pld_y_bit = -1;
+static int hf_vp8_pld_keyidx = -1;
+
+/* payload header fields */
+static int hf_vp8_hdr_frametype = -1;
+static int hf_vp8_hdr_version = -1;
+static int hf_vp8_hdr_show_bit = -1;
+static int hf_vp8_hdr_first_partition_size = -1;
+
+/* keyframe fields */
+static int hf_vp8_keyframe_start_code = -1;
+static int hf_vp8_keyframe_width = -1;
+static int hf_vp8_keyframe_horizontal_scale = -1;
+static int hf_vp8_keyframe_height = -1;
+static int hf_vp8_keyframe_vertical_scale = -1;
+
+/* Initialize the subtree pointers */
+static int ett_vp8 = -1;
+static int ett_vp8_payload_descriptor = -1;
+static int ett_vp8_payload_header = -1;
+static int ett_vp8_payload = -1;
+static int ett_vp8_keyframe = -1;
+
+static expert_field ei_vp8_startcode = EI_INIT;
+static expert_field ei_vp8_undecoded = EI_INIT;
+
+static void
+dissect_vp8_payload_descriptor(tvbuff_t *tvb _U_, packet_info *pinfo, proto_tree *vp8_tree _U_, gint *offset, gboolean *hasHeader);
+
+static void
+dissect_vp8_payload_header(tvbuff_t *tvb _U_, packet_info *pinfo, proto_tree *vp8_tree _U_, gint *offset, gint *frametype, gint *partition1_size);
+
+static void
+dissect_vp8_payload(tvbuff_t *tvb _U_, packet_info *pinfo, proto_tree *vp8_tree _U_, gint *offset, gint *frametype, gint *partition1_size);
+
+static gint *ett[] = {
+        &ett_vp8,
+        &ett_vp8_payload_descriptor,
+        &ett_vp8_payload_header,
+        &ett_vp8_payload,
+        &ett_vp8_keyframe
+};
+
+static const value_string vp8_type_values[] = {
+    {  0,   "Keyframe" },
+    {  1,   "Interframe" },
+    {  2,   "Continuation" },
+    {  3 , NULL }
+    
+};
+
+static const true_false_string vp8_x_bit_vals = {
+  "Extended control bits present (I L T K)",
+  "Extended control bits not present"
+};
+
+static const true_false_string vp8_r_bit_vals = {
+  "Reserved for future use (Error should be zero)",
+  "Reserved for future use"
+};
+
+static const true_false_string vp8_n_bit_vals = {
+  "Non referenced frame",
+  "Reference frame"
+};
+
+static const true_false_string vp8_s_bit_vals = {
+  "Start of VP8 partition",
+  "Continuation of VP8 partition"
+};
+
+static const true_false_string vp8_i_bit_vals = {
+  "Picture ID byte present",
+  "No Picture byte ID"
+};
+
+static const true_false_string vp8_l_bit_vals = {
+  "TL0PICIDX byte present",
+  "TL0PICIDX byte not present"
+};
+
+static const true_false_string vp8_t_bit_vals = {
+  "TID (temporal layer index) byte present",
+  "TID (temporal layer index) byte not present"
+};
+
+static const true_false_string vp8_k_bit_vals = {
+  "TID/KEYIDX byte present",
+  "TID/KEYIDX byte not present"
+};
+
+static const true_false_string vp8_hdr_frametype_vals = {
+  "interframe",
+  "keyframe"
+};
+
+void proto_reg_handoff_vp8(void);
+
+static void
+dissect_vp8(tvbuff_t *tvb _U_, packet_info *pinfo, proto_tree *tree _U_)
+{
+
+    proto_item *item _U_;
+    gint offset= 0, frametype = 0, partition1_size = -1;
+    proto_tree *vp8_tree, *vp8_payload_tree _U_;
+    gboolean hasHeader = FALSE;
+
+    col_set_str(pinfo->cinfo, COL_PROTOCOL, "VP8");
+        
+    item = proto_tree_add_item(tree, proto_vp8, tvb, 0, -1, ENC_NA);
+    vp8_tree = proto_item_add_subtree(item, ett_vp8);
+
+    frametype=2;/*continuation, will get overridden if there is a payload header*/
+        
+    dissect_vp8_payload_descriptor(tvb, pinfo, vp8_tree, &offset, &hasHeader);
+    if (hasHeader)
+    {
+        dissect_vp8_payload_header(tvb, pinfo, vp8_tree, &offset, &frametype, &partition1_size);
+    }
+
+    dissect_vp8_payload(tvb, pinfo, vp8_tree, &offset, &frametype, &partition1_size);
+
+    col_append_fstr(pinfo->cinfo, COL_INFO, " - %s",
+        val_to_str(frametype, vp8_type_values, "Unknown Type (%u)"));
+}
+
+static void
+dissect_vp8_payload_descriptor(tvbuff_t *tvb _U_, packet_info *pinfo _U_, proto_tree *vp8_tree _U_, gint *offset, gboolean *hasHeader)
+{
+    proto_item *item_descriptor _U_, *ti _U_= NULL;
+    guint8      extended_bit, s_bit, partId;
+    proto_tree *vp8_payload_descriptor_tree;
+
+/*
+The first octets after the RTP header are the VP8 payload descriptor,
+   with the following structure.
+
+         0 1 2 3 4 5 6 7
+        +-+-+-+-+-+-+-+-+
+        |X|R|N|S|PartID | (REQUIRED)
+        +-+-+-+-+-+-+-+-+
+   X:   |I|L|T|K| RSV   | (OPTIONAL)
+        +-+-+-+-+-+-+-+-+
+   I:   |   PictureID   | (OPTIONAL)
+        +-+-+-+-+-+-+-+-+
+   L:   |   TL0PICIDX   | (OPTIONAL)
+        +-+-+-+-+-+-+-+-+
+   T/K: |TID|Y| KEYIDX  | (OPTIONAL)
+        +-+-+-+-+-+-+-+-+
+*/
+
+        item_descriptor = proto_tree_add_text(vp8_tree, tvb, *offset, -1, "Payload descriptor");
+        vp8_payload_descriptor_tree = proto_item_add_subtree(item_descriptor, ett_vp8_payload_descriptor);
+
+        proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_x_bit, tvb, *offset, 1, ENC_BIG_ENDIAN);
+        proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_r_bit, tvb, *offset, 1, ENC_BIG_ENDIAN);
+        proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_n_bit, tvb, *offset, 1, ENC_BIG_ENDIAN);
+        proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_s_bit, tvb, *offset, 1, ENC_BIG_ENDIAN);
+        proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_part_id, tvb, *offset, 1, ENC_BIG_ENDIAN);
+        extended_bit = tvb_get_guint8(tvb, *offset) & BIT_1_MASK;
+        s_bit = tvb_get_guint8(tvb, *offset) & BIT_4_MASK;
+        partId = tvb_get_guint8(tvb, *offset) & BIT_5678_MASK;
+
+        if (s_bit>0 && partId==0) {
+            *hasHeader=TRUE;
+        }
+
+        if (extended_bit)
+        {
+            guint8 i_bit, l_bit, t_bit, k_bit;
+            (*offset)++;
+            proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_i_bit, tvb, *offset, 1, ENC_BIG_ENDIAN);
+            proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_l_bit, tvb, *offset, 1, ENC_BIG_ENDIAN);
+            proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_t_bit, tvb, *offset, 1, ENC_BIG_ENDIAN);
+            proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_k_bit, tvb, *offset, 1, ENC_BIG_ENDIAN);
+            proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_rsv_a, tvb, *offset, 1, ENC_BIG_ENDIAN);
+
+            i_bit = tvb_get_guint8(tvb, *offset) & BIT_1_MASK;
+            l_bit = tvb_get_guint8(tvb, *offset) & BIT_2_MASK;
+            t_bit = tvb_get_guint8(tvb, *offset) & BIT_3_MASK;
+            k_bit = tvb_get_guint8(tvb, *offset) & BIT_4_MASK;
+            if (i_bit)
+            {
+                (*offset)++;
+                if(tvb_get_guint8(tvb, *offset) & BIT_1_MASK)
+                {
+                    proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_extended_picture_id, tvb, *offset, 2, ENC_BIG_ENDIAN);
+                    (*offset)++;
+                }
+                else
+                {
+                    proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_picture_id, tvb, *offset, 1, ENC_BIG_ENDIAN);
+                }
+
+            }
+            if (l_bit)
+            {
+                (*offset)++;
+                proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_tl0picidx, tvb, *offset, 1, ENC_BIG_ENDIAN);
+            }
+            if (t_bit || k_bit)
+            {
+                (*offset)++;
+                proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_tid, tvb, *offset, 1, ENC_BIG_ENDIAN);
+                proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_y_bit, tvb, *offset, 1, ENC_BIG_ENDIAN);
+                proto_tree_add_item(vp8_payload_descriptor_tree, hf_vp8_pld_keyidx, tvb, *offset, 1, ENC_BIG_ENDIAN);
+            }
+        }
+        (*offset)++;
+        /* now we know the length of payload descriptor */
+        proto_item_set_len(item_descriptor, *offset);
+}
+
+static void
+dissect_vp8_payload_header(tvbuff_t *tvb _U_, packet_info *pinfo _U_, proto_tree *vp8_tree _U_, gint *offset, gint *frametype, gint *partition1_size)
+{
+    proto_item *item_header _U_= NULL, *ti _U_;
+    proto_tree *vp8_payload_header_tree;
+    gint size0, size1, size2;
+
+/*
+The first three octets of an encoded VP8 frame are referred to as an
+   "uncompressed data chunk" in [RFC6386], and co-serve as payload
+   header in this RTP format.  The codec bitstream format specifies two
+   different variants of the uncompressed data chunk: a 3 octet version
+   for interframes and a 10 octet version for key frames.  The first 3
+   octets are common to both variants.  In the case of a key frame the
+   remaining 7 octets are considered to be part of the remaining payload
+   in this RTP format.  Note that the header is present only in packets
+   which have the S bit equal to one and the PartID equal to zero in the
+   payload descriptor.  Subsequent packets for the same frame do not
+   carry the payload header.
+
+
+      0 1 2 3 4 5 6 7
+     +-+-+-+-+-+-+-+-+
+     |Size0|H| VER |P|
+     +-+-+-+-+-+-+-+-+
+     |     Size1     |
+     +-+-+-+-+-+-+-+-+
+     |     Size2     |
+     +-+-+-+-+-+-+-+-+
+     | Bytes 4..N of |
+     | VP8 payload   |
+     :               :
+     +-+-+-+-+-+-+-+-+
+     | OPTIONAL RTP  |
+     | padding       |
+     :               :
+     +-+-+-+-+-+-+-+-+
+
+*/
+
+        item_header = proto_tree_add_text(vp8_tree, tvb, *offset, 3, "Payload header");
+        vp8_payload_header_tree = proto_item_add_subtree(item_header, ett_vp8_payload_header);
+        proto_tree_add_item(vp8_payload_header_tree, hf_vp8_hdr_frametype, tvb, *offset, 1, ENC_BIG_ENDIAN);
+        proto_tree_add_item(vp8_payload_header_tree, hf_vp8_hdr_version, tvb, *offset, 1, ENC_BIG_ENDIAN);
+        proto_tree_add_item(vp8_payload_header_tree, hf_vp8_hdr_show_bit, tvb, *offset, 1, ENC_BIG_ENDIAN);
+
+        *frametype = tvb_get_guint8(tvb, *offset) & BIT_8_MASK;
+        
+        size0 = (tvb_get_guint8(tvb, *offset) & BIT_123_MASK) >> 5;
+        size1 = tvb_get_guint8(tvb, *offset + 1);
+        size2 = tvb_get_guint8(tvb, *offset + 2);
+        (*partition1_size) = size0 + (size1*8) + (size2*2048);
+        proto_tree_add_uint(vp8_payload_header_tree, hf_vp8_hdr_first_partition_size, tvb, *offset, 3, *partition1_size);
+        (*offset)++;
+        (*offset)++;
+        (*offset)++;
+
+}
+
+static void
+dissect_vp8_payload(tvbuff_t *tvb _U_, packet_info *pinfo _U_, proto_tree *vp8_tree _U_, gint *offset, gint *frametype, gint *partition1_size) 
+{
+    proto_item *item_payload = NULL;
+    proto_tree *vp8_payload_tree _U_;
+    gint remainder;
+    
+    item_payload = proto_tree_add_text(vp8_tree, tvb, *offset, -1, "Payload");
+    vp8_payload_tree = proto_item_add_subtree(item_payload, ett_vp8_payload);
+
+    if (*frametype==0)
+    {
+        guint16 width, height;
+        gint start1, start2, start3, horizontal_scale, vertical_scale;
+        proto_tree *vp8_keyframe_tree _U_;
+        proto_item *item_keyframe = NULL;
+    
+        item_keyframe = proto_tree_add_text(vp8_payload_tree, tvb, *offset, -1, "Keyframe header");
+        vp8_keyframe_tree = proto_item_add_subtree(item_keyframe, ett_vp8_keyframe);
+        
+        proto_tree_add_item(vp8_keyframe_tree, hf_vp8_keyframe_start_code, tvb, *offset, 3, ENC_BIG_ENDIAN);
+        start1 = tvb_get_guint8(tvb, *offset);
+        start2 = tvb_get_guint8(tvb, *offset + 1);
+        start3 = tvb_get_guint8(tvb, *offset + 2);
+
+        /* check start code is correct */
+        if (start1!=0x9d||start2!=0x01||start3!=0x2a)
+        {
+            expert_add_info(pinfo, vp8_keyframe_tree, &ei_vp8_startcode);
+        }
+
+        (*offset)++;
+        (*offset)++;
+        (*offset)++;
+        width = tvb_get_letohs(tvb, *offset) & 0x3FFF;
+        horizontal_scale = tvb_get_letohs(tvb, *offset)>>14;
+
+        proto_tree_add_uint(vp8_keyframe_tree, hf_vp8_keyframe_horizontal_scale, tvb, *offset, 2, horizontal_scale);
+        proto_tree_add_uint(vp8_keyframe_tree, hf_vp8_keyframe_width, tvb, *offset, 2, width);
+        (*offset)++;
+        (*offset)++;
+
+        height = tvb_get_letohs(tvb, *offset) & 0x3FFF;
+        vertical_scale = tvb_get_letohs(tvb, *offset)>>14;
+        proto_tree_add_uint(vp8_keyframe_tree, hf_vp8_keyframe_vertical_scale, tvb, *offset, 2, vertical_scale);
+        proto_tree_add_uint(vp8_keyframe_tree, hf_vp8_keyframe_height, tvb, *offset, 2, height);
+        (*offset)++;
+        (*offset)++;
+    }
+
+    remainder = tvb_reported_length_remaining(tvb, (*offset));
+    if ((*partition1_size)==-1)
+    {
+        /*no header, continuation?*/
+        proto_tree_add_text(vp8_payload_tree, tvb, *offset, -1, "Continuation of partition fragment (%d bytes)", remainder);
+    }
+    else
+    { 
+        if (remainder < *partition1_size)
+        {
+            /* partition size has already been added to vp8 header tree, but it would be useful to provide additional explanation */
+            proto_tree_add_text(vp8_payload_tree, tvb, *offset, -1, "First partition is split with %d bytes in this packet and %d bytes in subsequent frames", remainder, ((*partition1_size)-remainder));
+        }
+        else
+        {
+            (*offset)= (*offset)+(*partition1_size);
+            proto_tree_add_text(vp8_payload_tree, tvb, *offset, -1, "This frame contains all of first partition (%d bytes) and also %d bytes from other partitions", *partition1_size, remainder);
+        }
+    }
+    expert_add_info(pinfo, vp8_payload_tree, &ei_vp8_undecoded);
+}
+
+void
+proto_register_vp8(void)
+{
+    module_t *vp8_module;
+    expert_module_t* expert_vp8;
+
+    static hf_register_info hf[] = {
+        { &hf_vp8_pld_x_bit,
+            { "X bit",           "vp8.pld.x",
+            FT_BOOLEAN, 8, TFS(&vp8_x_bit_vals), BIT_1_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_r_bit,
+            { "R bit",           "vp8.pld.r",
+            FT_BOOLEAN, 8, TFS(&vp8_r_bit_vals), BIT_2_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_n_bit,
+            { "N bit",           "vp8.pld.n",
+            FT_BOOLEAN, 8, TFS(&vp8_n_bit_vals), BIT_3_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_s_bit,
+            { "S bit",           "vp8.pld.s",
+            FT_BOOLEAN, 8, TFS(&vp8_s_bit_vals), BIT_4_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_part_id,
+            { "Part Id",           "vp8.pld.partid",
+            FT_UINT8, BASE_DEC, NULL, BIT_5678_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_i_bit,
+            { "I bit",           "vp8.pld.i",
+            FT_BOOLEAN, 8, TFS(&vp8_i_bit_vals), BIT_1_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_l_bit,
+            { "L bit",           "vp8.pld.l",
+            FT_BOOLEAN, 8, TFS(&vp8_l_bit_vals), BIT_2_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_t_bit,
+            { "T bit",           "vp8.pld.t",
+            FT_BOOLEAN, 8, TFS(&vp8_t_bit_vals), BIT_3_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_k_bit,
+            { "K bit",           "vp8.pld.k",
+            FT_BOOLEAN, 8, TFS(&vp8_k_bit_vals), BIT_4_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_rsv_a,
+            { "Reserved A",           "vp8.pld.rsva",
+            FT_UINT8, BASE_DEC, NULL, BIT_5678_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_picture_id,
+            { "Picture Id",           "vp8.pld.pictureid",
+            FT_UINT8, BASE_DEC, NULL, BIT_NO_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_extended_picture_id,
+            { "Extended Picture Id",           "vp8.pld.pictureid",
+            FT_UINT8, BASE_DEC, NULL, BIT_EXT_PICTURE_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_tl0picidx,
+            { "Temporal layer zero Picture Index (TL0PICIDX)",           "vp8.pld.tl0picidx",
+            FT_UINT8, BASE_DEC, NULL, BIT_NO_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_tid,
+            { "Temporal layer Index (TID)",           "vp8.pld.tid",
+            FT_UINT8, BASE_DEC, NULL, BIT_12_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_y_bit,
+            { "1 Lay Sync Bit (Y)",           "vp8.pld.y",
+            FT_BOOLEAN, 8, NULL, BIT_3_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_pld_keyidx,
+            { "Temporal Key Frame Index (KEYIDX)",           "vp8.pld.keyidx",
+            FT_UINT8, BASE_DEC, NULL, BIT_45678_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_hdr_frametype,
+            { "frametype",           "vp8.hdr.frametype",
+            FT_BOOLEAN, 8, TFS(&vp8_hdr_frametype_vals), BIT_8_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_hdr_version,
+            { "version",           "vp8.hdr.version",
+            FT_UINT8, BASE_DEC, NULL, BIT_567_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_hdr_show_bit,
+            { "Show bit",           "vp8.hdr.show",
+            FT_BOOLEAN, 8, NULL, BIT_5_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_hdr_first_partition_size,
+            { "First partition size",           "vp8.hdr.partition_size",
+            FT_UINT8, BASE_DEC, NULL, BIT_PARTITION_SIZE_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_keyframe_start_code,
+            { "VP8 Start code",           "vp8.keyframe.start_code",
+            FT_UINT24, BASE_HEX, NULL, BIT_3BYTE_NO_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_keyframe_width,
+            { "Width",           "vp8.keyframe.width",
+            FT_UINT16, BASE_DEC, NULL, BIT_2BYTE_NO_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_keyframe_height,
+            { "Height",           "vp8.keyframe.height",
+            FT_UINT16, BASE_DEC, NULL, BIT_2BYTE_NO_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_keyframe_horizontal_scale,
+            { "Horizontal Scale",           "vp8.keyframe.horizontal_scale",
+            FT_UINT8, BASE_DEC, NULL, BIT_12_MASK,
+            NULL, HFILL }
+        },
+        { &hf_vp8_keyframe_vertical_scale,
+            { "Vertical Scale",           "vp8.keyframe.vertical_scale",
+            FT_UINT8, BASE_DEC, NULL, BIT_12_MASK,
+            NULL, HFILL }
+        }
+
+    };
+
+    static ei_register_info ei[] = {
+        { &ei_vp8_startcode, { "vp8.keyframe.startcode", PI_PROTOCOL, PI_ERROR, "Startcode is incorrect", EXPFILL }},
+        { &ei_vp8_undecoded, { "vp8.undecoded", PI_UNDECODED, PI_NOTE, "Payload not fully decoded", EXPFILL }}
+    };
+
+    proto_vp8 = proto_register_protocol (
+        "VP8", /* name       */
+        "VP8",      /* short name */
+        "vp8"       /* abbrev     */
+        );
+
+    proto_register_field_array(proto_vp8, hf, array_length(hf));
+    proto_register_subtree_array(ett, array_length(ett));
+    
+    vp8_module = prefs_register_protocol(proto_vp8, proto_reg_handoff_vp8);
+
+    expert_vp8 = expert_register_protocol(proto_vp8);
+    expert_register_field_array(expert_vp8, ei, array_length(ei));
+
+    prefs_register_range_preference(vp8_module, "dynamic.payload.type",
+                            "vp8 dynamic payload types",
+                            "Dynamic payload types which will be interpreted as vp8"
+                            "; Values must be in the range 96 - 127",
+                            &temp_dynamic_payload_type_range, 127);
+
+    register_dissector("vp8", dissect_vp8, proto_vp8);
+}
+
+static void range_delete_vp8_rtp_pt_callback(guint32 rtp_pt) {
+    if (rtp_pt >= 96 && rtp_pt <= 127)
+        dissector_delete_uint("rtp.pt", rtp_pt, vp8_handle);
+}
+
+static void range_add_vp8_rtp_pt_callback(guint32 rtp_pt) {
+    if (rtp_pt >= 96 && rtp_pt <= 127)
+        dissector_add_uint("rtp.pt", rtp_pt, vp8_handle);
+}
+
+void
+proto_reg_handoff_vp8(void)
+{
+    static range_t  *dynamic_payload_type_range = NULL;
+    static gboolean  vp8_prefs_initialized     = FALSE;
+
+    if (!vp8_prefs_initialized) {
+        dissector_handle_t vp8_name_handle _U_;
+
+        vp8_handle = find_dissector("vp8");
+        dissector_add_string("rtp_dyn_payload_type","VP8", vp8_handle);
+
+        vp8_handle = create_dissector_handle(dissect_vp8, proto_vp8);
+
+    } else {
+        range_foreach(dynamic_payload_type_range, range_delete_vp8_rtp_pt_callback);
+        g_free(dynamic_payload_type_range);
+    }
+
+    dynamic_payload_type_range = range_copy(temp_dynamic_payload_type_range);
+    range_foreach(dynamic_payload_type_range, range_add_vp8_rtp_pt_callback);
+}