diff -r 4c282e7dd6d3 -r 5505e8908944 gst_plugins_base/gst-libs/gst/rtp/gstrtpbuffer.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gst_plugins_base/gst-libs/gst/rtp/gstrtpbuffer.c	Fri Jan 22 09:59:59 2010 +0200
@@ -0,0 +1,1265 @@
+/* GStreamer
+ * Copyright (C) <2005> Philippe Khalaf <burger@speedy.org>
+ * Copyright (C) <2006> Wim Taymans <wim@fluendo.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/**
+ * SECTION:gstrtpbuffer
+ * @short_description: Helper methods for dealing with RTP buffers
+ * @see_also: #GstBaseRTPPayload, #GstBaseRTPDepayload, gstrtcpbuffer
+ *
+ * <refsect2>
+ * <para>
+ * The GstRTPBuffer helper functions makes it easy to parse and create regular 
+ * #GstBuffer objects that contain RTP payloads. These buffers are typically of
+ * 'application/x-rtp' #GstCaps.
+ * </para>
+ * </refsect2>
+ *
+ * Last reviewed on 2006-07-17 (0.10.10)
+ */
+
+#include "gstrtpbuffer.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#define GST_RTP_HEADER_LEN 12
+
+/* Note: we use bitfields here to make sure the compiler doesn't add padding
+ * between fields on certain architectures; can't assume aligned access either
+ */
+typedef struct _GstRTPHeader
+{
+#if G_BYTE_ORDER == G_LITTLE_ENDIAN
+  unsigned int csrc_count:4;    /* CSRC count */
+  unsigned int extension:1;     /* header extension flag */
+  unsigned int padding:1;       /* padding flag */
+  unsigned int version:2;       /* protocol version */
+  unsigned int payload_type:7;  /* payload type */
+  unsigned int marker:1;        /* marker bit */
+#elif G_BYTE_ORDER == G_BIG_ENDIAN
+  unsigned int version:2;       /* protocol version */
+  unsigned int padding:1;       /* padding flag */
+  unsigned int extension:1;     /* header extension flag */
+  unsigned int csrc_count:4;    /* CSRC count */
+  unsigned int marker:1;        /* marker bit */
+  unsigned int payload_type:7;  /* payload type */
+#else
+#error "G_BYTE_ORDER should be big or little endian."
+#endif
+  unsigned int seq:16;          /* sequence number */
+  unsigned int timestamp:32;    /* timestamp */
+  unsigned int ssrc:32;         /* synchronization source */
+  guint8 csrclist[4];           /* optional CSRC list, 32 bits each */
+} GstRTPHeader;
+
+#define GST_RTP_HEADER_VERSION(buf)     (((GstRTPHeader *)(GST_BUFFER_DATA (buf)))->version)
+#define GST_RTP_HEADER_PADDING(buf)     (((GstRTPHeader *)(GST_BUFFER_DATA (buf)))->padding)
+#define GST_RTP_HEADER_EXTENSION(buf)   (((GstRTPHeader *)(GST_BUFFER_DATA (buf)))->extension)
+#define GST_RTP_HEADER_CSRC_COUNT(buf)  (((GstRTPHeader *)(GST_BUFFER_DATA (buf)))->csrc_count)
+#define GST_RTP_HEADER_MARKER(buf)      (((GstRTPHeader *)(GST_BUFFER_DATA (buf)))->marker)
+#define GST_RTP_HEADER_PAYLOAD_TYPE(buf)(((GstRTPHeader *)(GST_BUFFER_DATA (buf)))->payload_type)
+#define GST_RTP_HEADER_SEQ(buf)         (((GstRTPHeader *)(GST_BUFFER_DATA (buf)))->seq)
+#define GST_RTP_HEADER_TIMESTAMP(buf)   (((GstRTPHeader *)(GST_BUFFER_DATA (buf)))->timestamp)
+#define GST_RTP_HEADER_SSRC(buf)        (((GstRTPHeader *)(GST_BUFFER_DATA (buf)))->ssrc)
+#define GST_RTP_HEADER_CSRC_LIST_OFFSET(buf,i)  \
+    GST_BUFFER_DATA (buf) +                     \
+    G_STRUCT_OFFSET(GstRTPHeader, csrclist) +   \
+    ((i) * sizeof(guint32))
+#define GST_RTP_HEADER_CSRC_SIZE(buf)   (GST_RTP_HEADER_CSRC_COUNT(buf) * sizeof (guint32))
+
+/**
+ * gst_rtp_buffer_allocate_data:
+ * @buffer: a #GstBuffer
+ * @payload_len: the length of the payload
+ * @pad_len: the amount of padding
+ * @csrc_count: the number of CSRC entries
+ *
+ * Allocate enough data in @buffer to hold an RTP packet with @csrc_count CSRCs,
+ * a payload length of @payload_len and padding of @pad_len.
+ * MALLOCDATA of @buffer will be overwritten and will not be freed. 
+ * All other RTP header fields will be set to 0/FALSE.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_rtp_buffer_allocate_data (GstBuffer * buffer, guint payload_len,
+    guint8 pad_len, guint8 csrc_count)
+{
+  guint len;
+
+  g_return_if_fail (csrc_count <= 15);
+  g_return_if_fail (GST_IS_BUFFER (buffer));
+
+  len = GST_RTP_HEADER_LEN + csrc_count * sizeof (guint32)
+      + payload_len + pad_len;
+
+  GST_BUFFER_MALLOCDATA (buffer) = g_malloc (len);
+  GST_BUFFER_DATA (buffer) = GST_BUFFER_MALLOCDATA (buffer);
+  GST_BUFFER_SIZE (buffer) = len;
+
+  /* fill in defaults */
+  GST_RTP_HEADER_VERSION (buffer) = GST_RTP_VERSION;
+  GST_RTP_HEADER_PADDING (buffer) = FALSE;
+  GST_RTP_HEADER_EXTENSION (buffer) = FALSE;
+  GST_RTP_HEADER_CSRC_COUNT (buffer) = csrc_count;
+  memset (GST_RTP_HEADER_CSRC_LIST_OFFSET (buffer, 0), 0,
+      csrc_count * sizeof (guint32));
+  GST_RTP_HEADER_MARKER (buffer) = FALSE;
+  GST_RTP_HEADER_PAYLOAD_TYPE (buffer) = 0;
+  GST_RTP_HEADER_SEQ (buffer) = 0;
+  GST_RTP_HEADER_TIMESTAMP (buffer) = 0;
+  GST_RTP_HEADER_SSRC (buffer) = 0;
+}
+
+/**
+ * gst_rtp_buffer_new_take_data:
+ * @data: data for the new buffer
+ * @len: the length of data
+ *
+ * Create a new buffer and set the data and size of the buffer to @data and @len
+ * respectively. @data will be freed when the buffer is unreffed, so this
+ * function transfers ownership of @data to the new buffer.
+ *
+ * Returns: A newly allocated buffer with @data and of size @len.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstBuffer *
+gst_rtp_buffer_new_take_data (gpointer data, guint len)
+{
+  GstBuffer *result;
+
+  g_return_val_if_fail (data != NULL, NULL);
+  g_return_val_if_fail (len > 0, NULL);
+
+  result = gst_buffer_new ();
+
+  GST_BUFFER_MALLOCDATA (result) = data;
+  GST_BUFFER_DATA (result) = data;
+  GST_BUFFER_SIZE (result) = len;
+
+  return result;
+}
+
+/**
+ * gst_rtp_buffer_new_copy_data:
+ * @data: data for the new buffer
+ * @len: the length of data
+ *
+ * Create a new buffer and set the data to a copy of @len
+ * bytes of @data and the size to @len. The data will be freed when the buffer
+ * is freed.
+ *
+ * Returns: A newly allocated buffer with a copy of @data and of size @len.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstBuffer *
+gst_rtp_buffer_new_copy_data (gpointer data, guint len)
+{
+  return gst_rtp_buffer_new_take_data (g_memdup (data, len), len);
+}
+
+/**
+ * gst_rtp_buffer_new_allocate:
+ * @payload_len: the length of the payload
+ * @pad_len: the amount of padding
+ * @csrc_count: the number of CSRC entries
+ *
+ * Allocate a new #Gstbuffer with enough data to hold an RTP packet with @csrc_count CSRCs,
+ * a payload length of @payload_len and padding of @pad_len.
+ * All other RTP header fields will be set to 0/FALSE.
+ *
+ * Returns: A newly allocated buffer that can hold an RTP packet with given
+ * parameters.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstBuffer *
+gst_rtp_buffer_new_allocate (guint payload_len, guint8 pad_len,
+    guint8 csrc_count)
+{
+  GstBuffer *result;
+
+  g_return_val_if_fail (csrc_count <= 15, NULL);
+
+  result = gst_buffer_new ();
+  gst_rtp_buffer_allocate_data (result, payload_len, pad_len, csrc_count);
+
+  return result;
+}
+
+/**
+ * gst_rtp_buffer_new_allocate_len:
+ * @packet_len: the total length of the packet
+ * @pad_len: the amount of padding
+ * @csrc_count: the number of CSRC entries
+ *
+ * Create a new #GstBuffer that can hold an RTP packet that is exactly
+ * @packet_len long. The length of the payload depends on @pad_len and
+ * @csrc_count and can be calculated with gst_rtp_buffer_calc_payload_len().
+ * All RTP header fields will be set to 0/FALSE.
+ *
+ * Returns: A newly allocated buffer that can hold an RTP packet of @packet_len.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstBuffer *
+gst_rtp_buffer_new_allocate_len (guint packet_len, guint8 pad_len,
+    guint8 csrc_count)
+{
+  guint len;
+
+  g_return_val_if_fail (csrc_count <= 15, NULL);
+
+  len = gst_rtp_buffer_calc_payload_len (packet_len, pad_len, csrc_count);
+
+  return gst_rtp_buffer_new_allocate (len, pad_len, csrc_count);
+}
+
+/**
+ * gst_rtp_buffer_calc_header_len:
+ * @csrc_count: the number of CSRC entries
+ *
+ * Calculate the header length of an RTP packet with @csrc_count CSRC entries.
+ * An RTP packet can have at most 15 CSRC entries.
+ *
+ * Returns: The length of an RTP header with @csrc_count CSRC entries.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint
+gst_rtp_buffer_calc_header_len (guint8 csrc_count)
+{
+  g_return_val_if_fail (csrc_count <= 15, 0);
+
+  return GST_RTP_HEADER_LEN + (csrc_count * sizeof (guint32));
+}
+
+/**
+ * gst_rtp_buffer_calc_packet_len:
+ * @payload_len: the length of the payload
+ * @pad_len: the amount of padding
+ * @csrc_count: the number of CSRC entries
+ *
+ * Calculate the total length of an RTP packet with a payload size of @payload_len,
+ * a padding of @pad_len and a @csrc_count CSRC entries.
+ *
+ * Returns: The total length of an RTP header with given parameters.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint
+gst_rtp_buffer_calc_packet_len (guint payload_len, guint8 pad_len,
+    guint8 csrc_count)
+{
+  g_return_val_if_fail (csrc_count <= 15, 0);
+
+  return payload_len + GST_RTP_HEADER_LEN + (csrc_count * sizeof (guint32))
+      + pad_len;
+}
+
+/**
+ * gst_rtp_buffer_calc_payload_len:
+ * @packet_len: the length of the total RTP packet
+ * @pad_len: the amount of padding
+ * @csrc_count: the number of CSRC entries
+ *
+ * Calculate the length of the payload of an RTP packet with size @packet_len,
+ * a padding of @pad_len and a @csrc_count CSRC entries.
+ *
+ * Returns: The length of the payload of an RTP packet  with given parameters.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint
+gst_rtp_buffer_calc_payload_len (guint packet_len, guint8 pad_len,
+    guint8 csrc_count)
+{
+  g_return_val_if_fail (csrc_count <= 15, 0);
+
+  return packet_len - GST_RTP_HEADER_LEN - (csrc_count * sizeof (guint32))
+      - pad_len;
+}
+
+/**
+ * gst_rtp_buffer_validate_data:
+ * @data: the data to validate
+ * @len: the length of @data to validate
+ *
+ * Check if the @data and @size point to the data of a valid RTP packet.
+ * This function checks the length, version and padding of the packet data.
+ * Use this function to validate a packet before using the other functions in
+ * this module.
+ *
+ * Returns: TRUE if the data points to a valid RTP packet.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_rtp_buffer_validate_data (guint8 * data, guint len)
+{
+  guint8 padding;
+  guint8 csrc_count;
+  guint header_len;
+  guint8 version;
+
+  g_return_val_if_fail (data != NULL, FALSE);
+
+  header_len = GST_RTP_HEADER_LEN;
+  if (G_UNLIKELY (len < header_len))
+    goto wrong_length;
+
+  /* check version */
+  version = (data[0] & 0xc0) >> 6;
+  if (G_UNLIKELY (version != GST_RTP_VERSION))
+    goto wrong_version;
+
+  /* calc header length with csrc */
+  csrc_count = (data[0] & 0x0f);
+  header_len += csrc_count * sizeof (guint32);
+
+  /* calc extension length when present. */
+  if (data[0] & 0x10) {
+    guint8 *extpos;
+    guint16 extlen;
+
+    /* this points to the extenstion bits and header length */
+    extpos = &data[header_len];
+
+    /* skip the header and check that we have enough space */
+    header_len += 4;
+    if (G_UNLIKELY (len < header_len))
+      goto wrong_length;
+
+    /* skip id */
+    extpos += 2;
+    /* read length as the number of 32 bits words */
+    extlen = GST_READ_UINT16_BE (extpos);
+
+    header_len += extlen * sizeof (guint32);
+  }
+
+  /* check for padding */
+  if (data[0] & 0x20)
+    padding = data[len - 1];
+  else
+    padding = 0;
+
+  /* check if padding not bigger than packet and header */
+  if (G_UNLIKELY (len - header_len < padding))
+    goto wrong_padding;
+
+  return TRUE;
+
+  /* ERRORS */
+wrong_length:
+  {
+    GST_DEBUG ("len < header_len check failed (%d < %d)", len, header_len);
+    return FALSE;
+  }
+wrong_version:
+  {
+    GST_DEBUG ("version check failed (%d != %d)", version, GST_RTP_VERSION);
+    return FALSE;
+  }
+wrong_padding:
+  {
+    GST_DEBUG ("padding check failed (%d - %d < %d)", len, header_len, padding);
+    return FALSE;
+  }
+}
+
+/**
+ * gst_rtp_buffer_validate:
+ * @buffer: the buffer to validate
+ *
+ * Check if the data pointed to by @buffer is a valid RTP packet using
+ * gst_rtp_buffer_validate_data().
+ *
+ * Returns: TRUE if @buffer is a valid RTP packet.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_rtp_buffer_validate (GstBuffer * buffer)
+{
+  guint8 *data;
+  guint len;
+
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
+
+  data = GST_BUFFER_DATA (buffer);
+  len = GST_BUFFER_SIZE (buffer);
+
+  return gst_rtp_buffer_validate_data (data, len);
+}
+
+/**
+ * gst_rtp_buffer_set_packet_len:
+ * @buffer: the buffer
+ * @len: the new packet length
+ *
+ * Set the total @buffer size to @len. The data in the buffer will be made
+ * larger if needed. Any padding will be removed from the packet. 
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_rtp_buffer_set_packet_len (GstBuffer * buffer, guint len)
+{
+  guint oldlen;
+
+  g_return_if_fail (GST_IS_BUFFER (buffer));
+
+  oldlen = GST_BUFFER_SIZE (buffer);
+
+  if (oldlen < len) {
+    guint8 *newdata;
+
+    newdata = g_realloc (GST_BUFFER_MALLOCDATA (buffer), len);
+    GST_BUFFER_MALLOCDATA (buffer) = newdata;
+    GST_BUFFER_DATA (buffer) = newdata;
+  }
+  GST_BUFFER_SIZE (buffer) = len;
+
+  /* remove any padding */
+  GST_RTP_HEADER_PADDING (buffer) = FALSE;
+}
+
+/**
+ * gst_rtp_buffer_get_packet_len:
+ * @buffer: the buffer
+ *
+ * Return the total length of the packet in @buffer.
+ *
+ * Returns: The total length of the packet in @buffer.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint
+gst_rtp_buffer_get_packet_len (GstBuffer * buffer)
+{
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
+
+  return GST_BUFFER_SIZE (buffer);
+}
+
+/**
+ * gst_rtp_buffer_get_header_len:
+ * @buffer: the buffer
+ *
+ * Return the total length of the header in @buffer. This include the length of
+ * the fixed header, the CSRC list and the extension header.
+ *
+ * Returns: The total length of the header in @buffer.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint
+gst_rtp_buffer_get_header_len (GstBuffer * buffer)
+{
+  guint len;
+
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
+
+  len = GST_RTP_HEADER_LEN + GST_RTP_HEADER_CSRC_SIZE (buffer);
+  if (GST_RTP_HEADER_EXTENSION (buffer))
+    len += GST_READ_UINT16_BE (GST_BUFFER_DATA (buffer) + len + 2) * 4 + 4;
+
+  return len;
+}
+
+/**
+ * gst_rtp_buffer_get_version:
+ * @buffer: the buffer
+ *
+ * Get the version number of the RTP packet in @buffer.
+ *
+ * Returns: The version of @buffer.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint8
+gst_rtp_buffer_get_version (GstBuffer * buffer)
+{
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, 0);
+
+  return GST_RTP_HEADER_VERSION (buffer);
+}
+
+/**
+ * gst_rtp_buffer_set_version:
+ * @buffer: the buffer
+ * @version: the new version
+ *
+ * Set the version of the RTP packet in @buffer to @version.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_rtp_buffer_set_version (GstBuffer * buffer, guint8 version)
+{
+  g_return_if_fail (GST_IS_BUFFER (buffer));
+  g_return_if_fail (version < 0x04);
+  g_return_if_fail (GST_BUFFER_DATA (buffer) != NULL);
+
+  GST_RTP_HEADER_VERSION (buffer) = version;
+}
+
+/**
+ * gst_rtp_buffer_get_padding:
+ * @buffer: the buffer
+ *
+ * Check if the padding bit is set on the RTP packet in @buffer.
+ *
+ * Returns: TRUE if @buffer has the padding bit set.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_rtp_buffer_get_padding (GstBuffer * buffer)
+{
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, FALSE);
+
+  return GST_RTP_HEADER_PADDING (buffer);
+}
+
+/**
+ * gst_rtp_buffer_set_padding:
+ * @buffer: the buffer
+ * @padding: the new padding
+ *
+ * Set the padding bit on the RTP packet in @buffer to @padding.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_rtp_buffer_set_padding (GstBuffer * buffer, gboolean padding)
+{
+  g_return_if_fail (GST_IS_BUFFER (buffer));
+  g_return_if_fail (GST_BUFFER_DATA (buffer) != NULL);
+
+  GST_RTP_HEADER_PADDING (buffer) = padding;
+}
+
+/**
+ * gst_rtp_buffer_pad_to:
+ * @buffer: the buffer
+ * @len: the new amount of padding
+ *
+ * Set the amount of padding in the RTP packet in @buffer to
+ * @len. If @len is 0, the padding is removed.
+ *
+ * NOTE: This function does not work correctly.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_rtp_buffer_pad_to (GstBuffer * buffer, guint len)
+{
+  g_return_if_fail (GST_IS_BUFFER (buffer));
+  g_return_if_fail (GST_BUFFER_DATA (buffer) != NULL);
+
+  if (len > 0)
+    GST_RTP_HEADER_PADDING (buffer) = TRUE;
+  else
+    GST_RTP_HEADER_PADDING (buffer) = FALSE;
+
+  /* FIXME, set the padding byte at the end of the payload data */
+}
+
+/**
+ * gst_rtp_buffer_get_extension:
+ * @buffer: the buffer
+ *
+ * Check if the extension bit is set on the RTP packet in @buffer.
+ * 
+ * Returns: TRUE if @buffer has the extension bit set.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_rtp_buffer_get_extension (GstBuffer * buffer)
+{
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, FALSE);
+
+  return GST_RTP_HEADER_EXTENSION (buffer);
+}
+
+/**
+ * gst_rtp_buffer_set_extension:
+ * @buffer: the buffer
+ * @extension: the new extension
+ *
+ * Set the extension bit on the RTP packet in @buffer to @extension.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_rtp_buffer_set_extension (GstBuffer * buffer, gboolean extension)
+{
+  g_return_if_fail (GST_IS_BUFFER (buffer));
+  g_return_if_fail (GST_BUFFER_DATA (buffer) != NULL);
+
+  GST_RTP_HEADER_EXTENSION (buffer) = extension;
+}
+
+/**
+ * gst_rtp_buffer_get_extension_data:
+ * @buffer: the buffer
+ * @bits: location for result bits
+ * @data: location for data
+ * @wordlen: location for length of @data in 32 bits words
+ *
+ * Get the extension data. @bits will contain the extension 16 bits of custom
+ * data. @data will point to the data in the extension and @wordlen will contain
+ * the length of @data in 32 bits words.
+ *
+ * If @buffer did not contain an extension, this function will return %FALSE
+ * with @bits, @data and @wordlen unchanged.
+ * 
+ * Returns: TRUE if @buffer had the extension bit set.
+ *
+ * Since: 0.10.15
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_rtp_buffer_get_extension_data (GstBuffer * buffer, guint16 * bits,
+    gpointer * data, guint * wordlen)
+{
+  guint len;
+  guint8 *pdata;
+
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, FALSE);
+
+  if (!GST_RTP_HEADER_EXTENSION (buffer))
+    return FALSE;
+
+  /* move to the extension */
+  len = GST_RTP_HEADER_LEN + GST_RTP_HEADER_CSRC_SIZE (buffer);
+  pdata = GST_BUFFER_DATA (buffer) + len;
+
+  if (bits)
+    *bits = GST_READ_UINT16_BE (pdata);
+  if (wordlen)
+    *wordlen = GST_READ_UINT16_BE (pdata + 2);
+  if (data)
+    *data = pdata + 4;
+
+  return TRUE;
+}
+
+/**
+ * gst_rtp_buffer_set_extension_data:
+ * @buffer: the buffer
+ * @bits: the bits specific for the extension
+ * @length: the length that counts the number of 32-bit words in
+ * the extension, excluding the extension header ( therefore zero is a valid length)
+ *
+ * Set the extension bit of the rtp buffer and fill in the @bits and @length of the
+ * extension header. It will refuse to set the extension data if the buffer is not
+ * large enough.
+ *
+ * Returns: True if done.
+ *
+ * Since : 0.10.18
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_rtp_buffer_set_extension_data (GstBuffer * buffer, guint16 bits,
+    guint16 length)
+{
+  guint32 min_size = 0;
+  guint8 *data;
+
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, FALSE);
+
+  gst_rtp_buffer_set_extension (buffer, TRUE);
+  min_size =
+      GST_RTP_HEADER_LEN + GST_RTP_HEADER_CSRC_SIZE (buffer) + 4 +
+      length * sizeof (guint32);
+
+  if (min_size > GST_BUFFER_SIZE (buffer)) {
+    GST_WARNING_OBJECT (buffer,
+        "rtp buffer too small: need more than %d bytes but only have %d bytes",
+        min_size, GST_BUFFER_SIZE (buffer));
+    return FALSE;
+  }
+
+  data =
+      GST_BUFFER_DATA (buffer) + GST_RTP_HEADER_LEN +
+      GST_RTP_HEADER_CSRC_SIZE (buffer);
+  GST_WRITE_UINT16_BE (data, bits);
+  GST_WRITE_UINT16_BE (data + 2, length);
+  return TRUE;
+}
+
+/**
+ * gst_rtp_buffer_get_ssrc:
+ * @buffer: the buffer
+ *
+ * Get the SSRC of the RTP packet in @buffer.
+ * 
+ * Returns: the SSRC of @buffer in host order.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint32
+gst_rtp_buffer_get_ssrc (GstBuffer * buffer)
+{
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, 0);
+
+  return g_ntohl (GST_RTP_HEADER_SSRC (buffer));
+}
+
+/**
+ * gst_rtp_buffer_set_ssrc:
+ * @buffer: the buffer
+ * @ssrc: the new SSRC
+ *
+ * Set the SSRC on the RTP packet in @buffer to @ssrc.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_rtp_buffer_set_ssrc (GstBuffer * buffer, guint32 ssrc)
+{
+  g_return_if_fail (GST_IS_BUFFER (buffer));
+  g_return_if_fail (GST_BUFFER_DATA (buffer) != NULL);
+
+  GST_RTP_HEADER_SSRC (buffer) = g_htonl (ssrc);
+}
+
+/**
+ * gst_rtp_buffer_get_csrc_count:
+ * @buffer: the buffer
+ *
+ * Get the CSRC count of the RTP packet in @buffer.
+ * 
+ * Returns: the CSRC count of @buffer.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint8
+gst_rtp_buffer_get_csrc_count (GstBuffer * buffer)
+{
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, 0);
+
+  return GST_RTP_HEADER_CSRC_COUNT (buffer);
+}
+
+/**
+ * gst_rtp_buffer_get_csrc:
+ * @buffer: the buffer
+ * @idx: the index of the CSRC to get
+ *
+ * Get the CSRC at index @idx in @buffer.
+ * 
+ * Returns: the CSRC at index @idx in host order.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint32
+gst_rtp_buffer_get_csrc (GstBuffer * buffer, guint8 idx)
+{
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, 0);
+  g_return_val_if_fail (idx < GST_RTP_HEADER_CSRC_COUNT (buffer), 0);
+
+  return GST_READ_UINT32_BE (GST_RTP_HEADER_CSRC_LIST_OFFSET (buffer, idx));
+}
+
+/**
+ * gst_rtp_buffer_set_csrc:
+ * @buffer: the buffer
+ * @idx: the CSRC index to set
+ * @csrc: the CSRC in host order to set at @idx
+ *
+ * Modify the CSRC at index @idx in @buffer to @csrc.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_rtp_buffer_set_csrc (GstBuffer * buffer, guint8 idx, guint32 csrc)
+{
+  g_return_if_fail (GST_IS_BUFFER (buffer));
+  g_return_if_fail (GST_BUFFER_DATA (buffer) != NULL);
+  g_return_if_fail (idx < GST_RTP_HEADER_CSRC_COUNT (buffer));
+
+  GST_WRITE_UINT32_BE (GST_RTP_HEADER_CSRC_LIST_OFFSET (buffer, idx), csrc);
+}
+
+/**
+ * gst_rtp_buffer_get_marker:
+ * @buffer: the buffer
+ *
+ * Check if the marker bit is set on the RTP packet in @buffer.
+ *
+ * Returns: TRUE if @buffer has the marker bit set.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_rtp_buffer_get_marker (GstBuffer * buffer)
+{
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, FALSE);
+
+  return GST_RTP_HEADER_MARKER (buffer);
+}
+
+/**
+ * gst_rtp_buffer_set_marker:
+ * @buffer: the buffer
+ * @marker: the new marker
+ *
+ * Set the marker bit on the RTP packet in @buffer to @marker.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_rtp_buffer_set_marker (GstBuffer * buffer, gboolean marker)
+{
+  g_return_if_fail (GST_IS_BUFFER (buffer));
+  g_return_if_fail (GST_BUFFER_DATA (buffer) != NULL);
+
+  GST_RTP_HEADER_MARKER (buffer) = marker;
+}
+
+/**
+ * gst_rtp_buffer_get_payload_type:
+ * @buffer: the buffer
+ *
+ * Get the payload type of the RTP packet in @buffer.
+ *
+ * Returns: The payload type.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint8
+gst_rtp_buffer_get_payload_type (GstBuffer * buffer)
+{
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, 0);
+
+  return GST_RTP_HEADER_PAYLOAD_TYPE (buffer);
+}
+
+/**
+ * gst_rtp_buffer_set_payload_type:
+ * @buffer: the buffer
+ * @payload_type: the new type
+ *
+ * Set the payload type of the RTP packet in @buffer to @payload_type.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_rtp_buffer_set_payload_type (GstBuffer * buffer, guint8 payload_type)
+{
+  g_return_if_fail (GST_IS_BUFFER (buffer));
+  g_return_if_fail (GST_BUFFER_DATA (buffer) != NULL);
+  g_return_if_fail (payload_type < 0x80);
+
+  GST_RTP_HEADER_PAYLOAD_TYPE (buffer) = payload_type;
+}
+
+/**
+ * gst_rtp_buffer_get_seq:
+ * @buffer: the buffer
+ *
+ * Get the sequence number of the RTP packet in @buffer.
+ *
+ * Returns: The sequence number in host order.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint16
+gst_rtp_buffer_get_seq (GstBuffer * buffer)
+{
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, 0);
+
+  return g_ntohs (GST_RTP_HEADER_SEQ (buffer));
+}
+
+/**
+ * gst_rtp_buffer_set_seq:
+ * @buffer: the buffer
+ * @seq: the new sequence number
+ *
+ * Set the sequence number of the RTP packet in @buffer to @seq.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_rtp_buffer_set_seq (GstBuffer * buffer, guint16 seq)
+{
+  g_return_if_fail (GST_IS_BUFFER (buffer));
+  g_return_if_fail (GST_BUFFER_DATA (buffer) != NULL);
+
+  GST_RTP_HEADER_SEQ (buffer) = g_htons (seq);
+}
+
+/**
+ * gst_rtp_buffer_get_timestamp:
+ * @buffer: the buffer
+ *
+ * Get the timestamp of the RTP packet in @buffer.
+ *
+ * Returns: The timestamp in host order.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint32
+gst_rtp_buffer_get_timestamp (GstBuffer * buffer)
+{
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, 0);
+
+  return g_ntohl (GST_RTP_HEADER_TIMESTAMP (buffer));
+}
+
+/**
+ * gst_rtp_buffer_set_timestamp:
+ * @buffer: the buffer
+ * @timestamp: the new timestamp
+ *
+ * Set the timestamp of the RTP packet in @buffer to @timestamp.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_rtp_buffer_set_timestamp (GstBuffer * buffer, guint32 timestamp)
+{
+  g_return_if_fail (GST_IS_BUFFER (buffer));
+  g_return_if_fail (GST_BUFFER_DATA (buffer) != NULL);
+
+  GST_RTP_HEADER_TIMESTAMP (buffer) = g_htonl (timestamp);
+}
+
+/**
+ * gst_rtp_buffer_get_payload_subbuffer:
+ * @buffer: the buffer
+ * @offset: the offset in the payload
+ * @len: the length in the payload
+ *
+ * Create a subbuffer of the payload of the RTP packet in @buffer. @offset bytes
+ * are skipped in the payload and the subbuffer will be of size @len.
+ * If @len is -1 the total payload starting from @offset if subbuffered.
+ *
+ * Returns: A new buffer with the specified data of the payload.
+ *
+ * Since: 0.10.10
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstBuffer *
+gst_rtp_buffer_get_payload_subbuffer (GstBuffer * buffer, guint offset,
+    guint len)
+{
+  guint poffset, plen;
+
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, NULL);
+
+  plen = gst_rtp_buffer_get_payload_len (buffer);
+  /* we can't go past the length */
+  if (G_UNLIKELY (offset >= plen)) {
+    GST_WARNING ("offset=%u should be less then plen=%u", offset, plen);
+    return (NULL);
+  }
+
+  /* apply offset */
+  poffset = gst_rtp_buffer_get_header_len (buffer) + offset;
+  plen -= offset;
+
+  /* see if we need to shrink the buffer based on @len */
+  if (len != -1 && len < plen)
+    plen = len;
+
+  return gst_buffer_create_sub (buffer, poffset, plen);
+}
+
+/**
+ * gst_rtp_buffer_get_payload_buffer:
+ * @buffer: the buffer
+ *
+ * Create a buffer of the payload of the RTP packet in @buffer. This function
+ * will internally create a subbuffer of @buffer so that a memcpy can be
+ * avoided.
+ *
+ * Returns: A new buffer with the data of the payload.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstBuffer *
+gst_rtp_buffer_get_payload_buffer (GstBuffer * buffer)
+{
+  return gst_rtp_buffer_get_payload_subbuffer (buffer, 0, -1);
+}
+
+/**
+ * gst_rtp_buffer_get_payload_len:
+ * @buffer: the buffer
+ *
+ * Get the length of the payload of the RTP packet in @buffer.
+ *
+ * Returns: The length of the payload in @buffer.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint
+gst_rtp_buffer_get_payload_len (GstBuffer * buffer)
+{
+  guint len, size;
+
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, 0);
+
+  size = GST_BUFFER_SIZE (buffer);
+
+  len = size - gst_rtp_buffer_get_header_len (buffer);
+
+  if (GST_RTP_HEADER_PADDING (buffer))
+    len -= GST_BUFFER_DATA (buffer)[size - 1];
+
+  return len;
+}
+
+/**
+ * gst_rtp_buffer_get_payload:
+ * @buffer: the buffer
+ *
+ * Get a pointer to the payload data in @buffer. This pointer is valid as long
+ * as a reference to @buffer is held.
+ *
+ * Returns: A pointer to the payload data in @buffer.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gpointer
+gst_rtp_buffer_get_payload (GstBuffer * buffer)
+{
+  g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
+  g_return_val_if_fail (GST_BUFFER_DATA (buffer) != NULL, NULL);
+
+  return GST_BUFFER_DATA (buffer) + gst_rtp_buffer_get_header_len (buffer);
+}
+
+/**
+ * gst_rtp_buffer_default_clock_rate:
+ * @payload_type: the static payload type
+ *
+ * Get the default clock-rate for the static payload type @payload_type.
+ *
+ * Returns: the default clock rate or -1 if the payload type is not static or
+ * the clock-rate is undefined.
+ *
+ * Since: 0.10.13
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint32
+gst_rtp_buffer_default_clock_rate (guint8 payload_type)
+{
+  const GstRTPPayloadInfo *info;
+  guint32 res;
+
+  info = gst_rtp_payload_info_for_pt (payload_type);
+  if (!info)
+    return -1;
+
+  res = info->clock_rate;
+  /* 0 means unknown so we have to return -1 from this function */
+  if (res == 0)
+    res = -1;
+
+  return res;
+}
+
+/**
+ * gst_rtp_buffer_compare_seqnum:
+ * @seqnum1: a sequence number
+ * @seqnum2: a sequence number
+ *
+ * Compare two sequence numbers, taking care of wraparounds.
+ *
+ * Returns: -1 if @seqnum1 is before @seqnum2, 0 if they are equal or 1 if
+ * @seqnum1 is bigger than @segnum2.
+ *
+ * Since: 0.10.15
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gint
+gst_rtp_buffer_compare_seqnum (guint16 seqnum1, guint16 seqnum2)
+{
+  /* check if diff more than half of the 16bit range */
+  if (abs (seqnum2 - seqnum1) > (1 << 15)) {
+    /* one of a/b has wrapped */
+    return seqnum1 - seqnum2;
+  } else {
+    return seqnum2 - seqnum1;
+  }
+}
+
+/**
+ * gst_rtp_buffer_ext_timestamp:
+ * @exttimestamp: a previous extended timestamp
+ * @timestamp: a new timestamp
+ *
+ * Update the @exttimestamp field with @timestamp. For the first call of the
+ * method, @exttimestamp should point to a location with a value of -1.
+ *
+ * This function makes sure that the returned value is a constantly increasing
+ * value even in the case where there is a timestamp wraparound.
+ *
+ * Returns: The extended timestamp of @timestamp.
+ *
+ * Since: 0.10.15
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint64
+gst_rtp_buffer_ext_timestamp (guint64 * exttimestamp, guint32 timestamp)
+{
+  guint64 result, diff, ext;
+
+  g_return_val_if_fail (exttimestamp != NULL, -1);
+
+  ext = *exttimestamp;
+
+  if (ext == -1) {
+    result = timestamp;
+  } else {
+    /* pick wraparound counter from previous timestamp and add to new timestamp */
+    result = timestamp + (ext & ~(G_GINT64_CONSTANT (0xffffffff)));
+
+    /* check for timestamp wraparound */
+    if (result < ext)
+      diff = ext - result;
+    else
+      diff = result - ext;
+
+    if (diff > G_MAXINT32) {
+      /* timestamp went backwards more than allowed, we wrap around and get
+       * updated extended timestamp. */
+      result += (G_GINT64_CONSTANT (1) << 32);
+    }
+  }
+  *exttimestamp = result;
+
+  return result;
+}