/* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstrtpbuffer
* @title: GstRTPBuffer
* @short_description: Helper methods for dealing with RTP buffers
* @see_also: #GstRTPBasePayload, #GstRTPBaseDepayload, gstrtcpbuffer
*
* 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.
*
*/
#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(data) (((GstRTPHeader *)(data))->version)
#define GST_RTP_HEADER_PADDING(data) (((GstRTPHeader *)(data))->padding)
#define GST_RTP_HEADER_EXTENSION(data) (((GstRTPHeader *)(data))->extension)
#define GST_RTP_HEADER_CSRC_COUNT(data) (((GstRTPHeader *)(data))->csrc_count)
#define GST_RTP_HEADER_MARKER(data) (((GstRTPHeader *)(data))->marker)
#define GST_RTP_HEADER_PAYLOAD_TYPE(data) (((GstRTPHeader *)(data))->payload_type)
#define GST_RTP_HEADER_SEQ(data) (((GstRTPHeader *)(data))->seq)
#define GST_RTP_HEADER_TIMESTAMP(data) (((GstRTPHeader *)(data))->timestamp)
#define GST_RTP_HEADER_SSRC(data) (((GstRTPHeader *)(data))->ssrc)
#define GST_RTP_HEADER_CSRC_LIST_OFFSET(data,i) \
data + G_STRUCT_OFFSET(GstRTPHeader, csrclist) + \
((i) * sizeof(guint32))
#define GST_RTP_HEADER_CSRC_SIZE(data) (GST_RTP_HEADER_CSRC_COUNT(data) * 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.
* @buffer must be writable and all previous memory in @buffer will be freed.
* If @pad_len is >0, the padding bit will be set. All other RTP header fields
* will be set to 0/FALSE.
*/
void
gst_rtp_buffer_allocate_data (GstBuffer * buffer, guint payload_len,
guint8 pad_len, guint8 csrc_count)
{
GstMapInfo map;
GstMemory *mem;
gsize hlen;
g_return_if_fail (csrc_count <= 15);
g_return_if_fail (GST_IS_BUFFER (buffer));
g_return_if_fail (gst_buffer_is_writable (buffer));
gst_buffer_remove_all_memory (buffer);
hlen = GST_RTP_HEADER_LEN + csrc_count * sizeof (guint32);
mem = gst_allocator_alloc (NULL, hlen, NULL);
gst_memory_map (mem, &map, GST_MAP_WRITE);
/* fill in defaults */
GST_RTP_HEADER_VERSION (map.data) = GST_RTP_VERSION;
if (pad_len)
GST_RTP_HEADER_PADDING (map.data) = TRUE;
else
GST_RTP_HEADER_PADDING (map.data) = FALSE;
GST_RTP_HEADER_EXTENSION (map.data) = FALSE;
GST_RTP_HEADER_CSRC_COUNT (map.data) = csrc_count;
memset (GST_RTP_HEADER_CSRC_LIST_OFFSET (map.data, 0), 0,
csrc_count * sizeof (guint32));
GST_RTP_HEADER_MARKER (map.data) = FALSE;
GST_RTP_HEADER_PAYLOAD_TYPE (map.data) = 0;
GST_RTP_HEADER_SEQ (map.data) = 0;
GST_RTP_HEADER_TIMESTAMP (map.data) = 0;
GST_RTP_HEADER_SSRC (map.data) = 0;
gst_memory_unmap (mem, &map);
gst_buffer_append_memory (buffer, mem);
if (payload_len) {
mem = gst_allocator_alloc (NULL, payload_len, NULL);
gst_buffer_append_memory (buffer, mem);
}
if (pad_len) {
mem = gst_allocator_alloc (NULL, pad_len, NULL);
gst_memory_map (mem, &map, GST_MAP_WRITE);
map.data[pad_len - 1] = pad_len;
gst_memory_unmap (mem, &map);
gst_buffer_append_memory (buffer, mem);
}
}
/**
* gst_rtp_buffer_new_take_data:
* @data: (array length=len) (transfer full) (element-type guint8):
* 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.
*/
GstBuffer *
gst_rtp_buffer_new_take_data (gpointer data, gsize len)
{
g_return_val_if_fail (data != NULL, NULL);
g_return_val_if_fail (len > 0, NULL);
return gst_buffer_new_wrapped (data, len);
}
/**
* gst_rtp_buffer_new_copy_data:
* @data: (array length=len) (element-type guint8): 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.
*/
GstBuffer *
gst_rtp_buffer_new_copy_data (gconstpointer data, gsize 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.
*/
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.
*/
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.
*/
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.
*/
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.
*/
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);
if (packet_len <
GST_RTP_HEADER_LEN + (csrc_count * sizeof (guint32)) + pad_len)
return 0;
return packet_len - GST_RTP_HEADER_LEN - (csrc_count * sizeof (guint32))
- pad_len;
}
/**
* gst_rtp_buffer_map:
* @buffer: a #GstBuffer
* @flags: #GstMapFlags
* @rtp: (out): a #GstRTPBuffer
*
* Map the contents of @buffer into @rtp.
*
* Returns: %TRUE if @buffer could be mapped.
*/
gboolean
gst_rtp_buffer_map (GstBuffer * buffer, GstMapFlags flags, GstRTPBuffer * rtp)
{
guint8 padding;
guint8 csrc_count;
guint header_len;
guint8 version, pt;
guint8 *data;
guint size;
gsize bufsize, skip;
guint idx, length;
guint n_mem;
g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
g_return_val_if_fail (rtp != NULL, FALSE);
g_return_val_if_fail (rtp->buffer == NULL, FALSE);
n_mem = gst_buffer_n_memory (buffer);
if (n_mem < 1)
goto no_memory;
/* map first memory, this should be the header */
if (!gst_buffer_map_range (buffer, 0, 1, &rtp->map[0], flags))
goto map_failed;
data = rtp->data[0] = rtp->map[0].data;
size = rtp->map[0].size;
/* the header must be completely in the first buffer */
header_len = GST_RTP_HEADER_LEN;
if (G_UNLIKELY (size < header_len))
goto wrong_length;
/* check version */
version = (data[0] & 0xc0);
if (G_UNLIKELY (version != (GST_RTP_VERSION << 6)))
goto wrong_version;
/* check reserved PT and marker bit, this is to check for RTCP
* packets. We do a relaxed check, you can still use 72-76 as long
* as the marker bit is cleared. */
pt = data[1];
if (G_UNLIKELY (pt >= 200 && pt <= 204))
goto reserved_pt;
/* calc header length with csrc */
csrc_count = (data[0] & 0x0f);
header_len += csrc_count * sizeof (guint32);
rtp->size[0] = header_len;
bufsize = gst_buffer_get_size (buffer);
/* calc extension length when present. */
if (data[0] & 0x10) {
guint8 *extdata;
guint16 extlen;
/* find memory for the extension bits, we find the block for the first 4
* bytes, all other extension bytes should also be in this block */
if (!gst_buffer_find_memory (buffer, header_len, 4, &idx, &length, &skip))
goto wrong_length;
if (!gst_buffer_map_range (buffer, idx, length, &rtp->map[1], flags))
goto map_failed;
extdata = rtp->data[1] = rtp->map[1].data + skip;
/* skip id */
extdata += 2;
/* read length as the number of 32 bits words */
extlen = GST_READ_UINT16_BE (extdata);
extlen *= sizeof (guint32);
/* add id and length */
extlen += 4;
/* all extension bytes must be in this block */
if (G_UNLIKELY (rtp->map[1].size < extlen))
goto wrong_length;
rtp->size[1] = extlen;
header_len += rtp->size[1];
} else {
rtp->data[1] = NULL;
rtp->size[1] = 0;
}
/* check for padding unless flags says to skip */
if ((data[0] & 0x20) != 0 &&
(flags & GST_RTP_BUFFER_MAP_FLAG_SKIP_PADDING) == 0) {
/* find memory for the padding bits */
if (!gst_buffer_find_memory (buffer, bufsize - 1, 1, &idx, &length, &skip))
goto wrong_length;
if (!gst_buffer_map_range (buffer, idx, length, &rtp->map[3], flags))
goto map_failed;
padding = rtp->map[3].data[skip];
rtp->data[3] = rtp->map[3].data + skip + 1 - padding;
rtp->size[3] = padding;
if (skip + 1 < padding)
goto wrong_length;
} else {
rtp->data[3] = NULL;
rtp->size[3] = 0;
padding = 0;
}
/* check if padding and header not bigger than packet length */
if (G_UNLIKELY (bufsize < padding + header_len))
goto wrong_padding;
rtp->buffer = buffer;
if (n_mem == 1) {
/* we have mapped the buffer already, so might just as well fill in the
* payload pointer and size and avoid another buffer map/unmap later */
rtp->data[2] = rtp->map[0].data + header_len;
rtp->size[2] = bufsize - header_len - padding;
} else {
/* we have not yet mapped the payload */
rtp->data[2] = NULL;
rtp->size[2] = 0;
}
/* rtp->state = 0; *//* unused */
return TRUE;
/* ERRORS */
no_memory:
{
GST_ERROR ("buffer without memory");
return FALSE;
}
map_failed:
{
GST_ERROR ("failed to map memory");
return FALSE;
}
wrong_length:
{
GST_DEBUG ("length check failed");
goto dump_packet;
}
wrong_version:
{
GST_DEBUG ("version check failed (%d != %d)", version, GST_RTP_VERSION);
goto dump_packet;
}
reserved_pt:
{
GST_DEBUG ("reserved PT %d found", pt);
goto dump_packet;
}
wrong_padding:
{
GST_DEBUG ("padding check failed (%" G_GSIZE_FORMAT " - %d < %d)", bufsize,
header_len, padding);
goto dump_packet;
}
dump_packet:
{
gint i;
GST_MEMDUMP ("buffer", data, size);
for (i = 0; i < G_N_ELEMENTS (rtp->map); ++i) {
if (rtp->map[i].memory != NULL)
gst_buffer_unmap (buffer, &rtp->map[i]);
}
return FALSE;
}
}
/**
* gst_rtp_buffer_unmap:
* @rtp: a #GstRTPBuffer
*
* Unmap @rtp previously mapped with gst_rtp_buffer_map().
*/
void
gst_rtp_buffer_unmap (GstRTPBuffer * rtp)
{
gint i;
g_return_if_fail (rtp != NULL);
g_return_if_fail (rtp->buffer != NULL);
for (i = 0; i < 4; i++) {
if (rtp->map[i].memory != NULL) {
gst_buffer_unmap (rtp->buffer, &rtp->map[i]);
rtp->map[i].memory = NULL;
}
rtp->data[i] = NULL;
rtp->size[i] = 0;
}
rtp->buffer = NULL;
}
/**
* gst_rtp_buffer_set_packet_len:
* @rtp: the RTP packet
* @len: the new packet length
*
* Set the total @rtp size to @len. The data in the buffer will be made
* larger if needed. Any padding will be removed from the packet.
*/
void
gst_rtp_buffer_set_packet_len (GstRTPBuffer * rtp, guint len)
{
guint8 *data;
data = rtp->data[0];
/* FIXME */
if (rtp->map[0].maxsize <= len) {
/* FIXME, realloc bigger space */
g_warning ("not implemented");
}
gst_buffer_set_size (rtp->buffer, len);
rtp->map[0].size = len;
/* remove any padding */
GST_RTP_HEADER_PADDING (data) = FALSE;
}
/**
* gst_rtp_buffer_get_packet_len:
* @rtp: the RTP packet
*
* Return the total length of the packet in @buffer.
*
* Returns: The total length of the packet in @buffer.
*/
guint
gst_rtp_buffer_get_packet_len (GstRTPBuffer * rtp)
{
return gst_buffer_get_size (rtp->buffer);
}
/**
* gst_rtp_buffer_get_header_len:
* @rtp: the RTP packet
*
* 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.
*/
guint
gst_rtp_buffer_get_header_len (GstRTPBuffer * rtp)
{
return rtp->size[0] + rtp->size[1];
}
/**
* gst_rtp_buffer_get_version:
* @rtp: the RTP packet
*
* Get the version number of the RTP packet in @buffer.
*
* Returns: The version of @buffer.
*/
guint8
gst_rtp_buffer_get_version (GstRTPBuffer * rtp)
{
return GST_RTP_HEADER_VERSION (rtp->data[0]);
}
/**
* gst_rtp_buffer_set_version:
* @rtp: the RTP packet
* @version: the new version
*
* Set the version of the RTP packet in @buffer to @version.
*/
void
gst_rtp_buffer_set_version (GstRTPBuffer * rtp, guint8 version)
{
g_return_if_fail (version < 0x04);
GST_RTP_HEADER_VERSION (rtp->data[0]) = version;
}
/**
* gst_rtp_buffer_get_padding:
* @rtp: the RTP packet
*
* Check if the padding bit is set on the RTP packet in @buffer.
*
* Returns: TRUE if @buffer has the padding bit set.
*/
gboolean
gst_rtp_buffer_get_padding (GstRTPBuffer * rtp)
{
return GST_RTP_HEADER_PADDING (rtp->data[0]);
}
/**
* gst_rtp_buffer_set_padding:
* @rtp: the buffer
* @padding: the new padding
*
* Set the padding bit on the RTP packet in @buffer to @padding.
*/
void
gst_rtp_buffer_set_padding (GstRTPBuffer * rtp, gboolean padding)
{
GST_RTP_HEADER_PADDING (rtp->data[0]) = padding;
}
/**
* gst_rtp_buffer_pad_to:
* @rtp: the RTP packet
* @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.
*/
void
gst_rtp_buffer_pad_to (GstRTPBuffer * rtp, guint len)
{
guint8 *data;
data = rtp->data[0];
if (len > 0)
GST_RTP_HEADER_PADDING (data) = TRUE;
else
GST_RTP_HEADER_PADDING (data) = FALSE;
/* FIXME, set the padding byte at the end of the payload data */
}
/**
* gst_rtp_buffer_get_extension:
* @rtp: the RTP packet
*
* Check if the extension bit is set on the RTP packet in @buffer.
*
* Returns: TRUE if @buffer has the extension bit set.
*/
gboolean
gst_rtp_buffer_get_extension (GstRTPBuffer * rtp)
{
return GST_RTP_HEADER_EXTENSION (rtp->data[0]);
}
/**
* gst_rtp_buffer_set_extension:
* @rtp: the RTP packet
* @extension: the new extension
*
* Set the extension bit on the RTP packet in @buffer to @extension.
*/
void
gst_rtp_buffer_set_extension (GstRTPBuffer * rtp, gboolean extension)
{
GST_RTP_HEADER_EXTENSION (rtp->data[0]) = extension;
}
/**
* gst_rtp_buffer_get_extension_data: (skip)
* @rtp: the RTP packet
* @bits: (out): location for result bits
* @data: (out) (array) (element-type guint8) (transfer none): location for data
* @wordlen: (out): 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.
*/
gboolean
gst_rtp_buffer_get_extension_data (GstRTPBuffer * rtp, guint16 * bits,
gpointer * data, guint * wordlen)
{
guint8 *pdata;
/* move to the extension */
pdata = rtp->data[1];
if (!pdata)
return FALSE;
if (bits)
*bits = GST_READ_UINT16_BE (pdata);
if (wordlen)
*wordlen = GST_READ_UINT16_BE (pdata + 2);
pdata += 4;
if (data)
*data = (gpointer *) pdata;
return TRUE;
}
/**
* gst_rtp_buffer_get_extension_bytes: (rename-to gst_rtp_buffer_get_extension_data)
* @rtp: the RTP packet
* @bits: (out): location for header bits
*
* Similar to gst_rtp_buffer_get_extension_data, but more suitable for language
* bindings usage. @bits will contain the extension 16 bits of custom data and
* the extension data (not including the extension header) is placed in a new
* #GBytes structure.
*
* If @rtp did not contain an extension, this function will return %NULL, with
* @bits unchanged. If there is an extension header but no extension data then
* an empty #GBytes will be returned.
*
* Returns: (transfer full): A new #GBytes if an extension header was present
* and %NULL otherwise.
*
* Since: 1.2
*/
GBytes *
gst_rtp_buffer_get_extension_bytes (GstRTPBuffer * rtp, guint16 * bits)
{
gpointer buf_data = NULL;
guint buf_len;
g_return_val_if_fail (rtp != NULL, FALSE);
if (!gst_rtp_buffer_get_extension_data (rtp, bits, &buf_data, &buf_len))
return NULL;
if (buf_len == 0) {
/* if no extension data is present return an empty GBytes */
buf_data = NULL;
}
/* multiply length with 4 to get length in bytes */
return g_bytes_new (buf_data, 4 * buf_len);
}
static gboolean
gst_rtp_buffer_map_payload (GstRTPBuffer * rtp)
{
guint hlen, plen;
guint idx, length;
gsize skip;
if (rtp->map[2].memory != NULL)
return TRUE;
hlen = gst_rtp_buffer_get_header_len (rtp);
plen = gst_buffer_get_size (rtp->buffer) - hlen - rtp->size[3];
if (!gst_buffer_find_memory (rtp->buffer, hlen, plen, &idx, &length, &skip))
return FALSE;
if (!gst_buffer_map_range (rtp->buffer, idx, length, &rtp->map[2],
rtp->map[0].flags))
return FALSE;
rtp->data[2] = rtp->map[2].data + skip;
rtp->size[2] = plen;
return TRUE;
}
/* ensure header, payload and padding are in separate buffers */
static void
ensure_buffers (GstRTPBuffer * rtp)
{
guint i, pos;
gboolean changed = FALSE;
/* make sure payload is mapped */
gst_rtp_buffer_map_payload (rtp);
for (i = 0, pos = 0; i < 4; i++) {
if (rtp->size[i]) {
gsize offset = (guint8 *) rtp->data[i] - rtp->map[i].data;
if (offset != 0 || rtp->map[i].size != rtp->size[i]) {
GstMemory *mem;
/* make copy */
mem = gst_memory_copy (rtp->map[i].memory, offset, rtp->size[i]);
/* insert new memory */
gst_buffer_insert_memory (rtp->buffer, pos, mem);
changed = TRUE;
}
pos++;
}
}
if (changed) {
GstBuffer *buf = rtp->buffer;
gst_rtp_buffer_unmap (rtp);
gst_buffer_remove_memory_range (buf, pos, -1);
gst_rtp_buffer_map (buf, GST_MAP_READWRITE, rtp);
}
}
/**
* gst_rtp_buffer_set_extension_data:
* @rtp: the RTP packet
* @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. If the existing extension data is not large enough, it will
* be made larger.
*
* Returns: True if done.
*/
gboolean
gst_rtp_buffer_set_extension_data (GstRTPBuffer * rtp, guint16 bits,
guint16 length)
{
guint32 min_size = 0;
guint8 *data;
GstMemory *mem = NULL;
ensure_buffers (rtp);
/* this is the size of the extension data we need */
min_size = 4 + length * sizeof (guint32);
/* we should allocate and map the extension data */
if (rtp->data[1] == NULL || min_size > rtp->size[1]) {
GstMapInfo map;
/* we don't have (enough) extension data, make some */
mem = gst_allocator_alloc (NULL, min_size, NULL);
if (rtp->data[1]) {
/* copy old data */
gst_memory_map (mem, &map, GST_MAP_WRITE);
memcpy (map.data, rtp->data[1], rtp->size[1]);
gst_memory_unmap (mem, &map);
/* unmap old */
gst_buffer_unmap (rtp->buffer, &rtp->map[1]);
gst_buffer_replace_memory (rtp->buffer, 1, mem);
} else {
/* we didn't have extension data, add */
gst_buffer_insert_memory (rtp->buffer, 1, mem);
}
/* map new */
gst_memory_map (mem, &rtp->map[1], GST_MAP_READWRITE);
gst_memory_ref (mem);
rtp->data[1] = rtp->map[1].data;
rtp->size[1] = rtp->map[1].size;
}
/* now we can set the extension bit */
data = rtp->data[0];
GST_RTP_HEADER_EXTENSION (data) = TRUE;
data = rtp->data[1];
GST_WRITE_UINT16_BE (data, bits);
GST_WRITE_UINT16_BE (data + 2, length);
return TRUE;
}
/**
* gst_rtp_buffer_get_ssrc:
* @rtp: the RTP packet
*
* Get the SSRC of the RTP packet in @buffer.
*
* Returns: the SSRC of @buffer in host order.
*/
guint32
gst_rtp_buffer_get_ssrc (GstRTPBuffer * rtp)
{
return g_ntohl (GST_RTP_HEADER_SSRC (rtp->data[0]));
}
/**
* gst_rtp_buffer_set_ssrc:
* @rtp: the RTP packet
* @ssrc: the new SSRC
*
* Set the SSRC on the RTP packet in @buffer to @ssrc.
*/
void
gst_rtp_buffer_set_ssrc (GstRTPBuffer * rtp, guint32 ssrc)
{
GST_RTP_HEADER_SSRC (rtp->data[0]) = g_htonl (ssrc);
}
/**
* gst_rtp_buffer_get_csrc_count:
* @rtp: the RTP packet
*
* Get the CSRC count of the RTP packet in @buffer.
*
* Returns: the CSRC count of @buffer.
*/
guint8
gst_rtp_buffer_get_csrc_count (GstRTPBuffer * rtp)
{
return GST_RTP_HEADER_CSRC_COUNT (rtp->data[0]);
}
/**
* gst_rtp_buffer_get_csrc:
* @rtp: the RTP packet
* @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.
*/
guint32
gst_rtp_buffer_get_csrc (GstRTPBuffer * rtp, guint8 idx)
{
guint8 *data;
data = rtp->data[0];
g_return_val_if_fail (idx < GST_RTP_HEADER_CSRC_COUNT (data), 0);
return GST_READ_UINT32_BE (GST_RTP_HEADER_CSRC_LIST_OFFSET (data, idx));
}
/**
* gst_rtp_buffer_set_csrc:
* @rtp: the RTP packet
* @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.
*/
void
gst_rtp_buffer_set_csrc (GstRTPBuffer * rtp, guint8 idx, guint32 csrc)
{
guint8 *data;
data = rtp->data[0];
g_return_if_fail (idx < GST_RTP_HEADER_CSRC_COUNT (data));
GST_WRITE_UINT32_BE (GST_RTP_HEADER_CSRC_LIST_OFFSET (data, idx), csrc);
}
/**
* gst_rtp_buffer_get_marker:
* @rtp: the RTP packet
*
* Check if the marker bit is set on the RTP packet in @buffer.
*
* Returns: TRUE if @buffer has the marker bit set.
*/
gboolean
gst_rtp_buffer_get_marker (GstRTPBuffer * rtp)
{
return GST_RTP_HEADER_MARKER (rtp->data[0]);
}
/**
* gst_rtp_buffer_set_marker:
* @rtp: the RTP packet
* @marker: the new marker
*
* Set the marker bit on the RTP packet in @buffer to @marker.
*/
void
gst_rtp_buffer_set_marker (GstRTPBuffer * rtp, gboolean marker)
{
GST_RTP_HEADER_MARKER (rtp->data[0]) = marker;
}
/**
* gst_rtp_buffer_get_payload_type:
* @rtp: the RTP packet
*
* Get the payload type of the RTP packet in @buffer.
*
* Returns: The payload type.
*/
guint8
gst_rtp_buffer_get_payload_type (GstRTPBuffer * rtp)
{
return GST_RTP_HEADER_PAYLOAD_TYPE (rtp->data[0]);
}
/**
* gst_rtp_buffer_set_payload_type:
* @rtp: the RTP packet
* @payload_type: the new type
*
* Set the payload type of the RTP packet in @buffer to @payload_type.
*/
void
gst_rtp_buffer_set_payload_type (GstRTPBuffer * rtp, guint8 payload_type)
{
g_return_if_fail (payload_type < 0x80);
GST_RTP_HEADER_PAYLOAD_TYPE (rtp->data[0]) = payload_type;
}
/**
* gst_rtp_buffer_get_seq:
* @rtp: the RTP packet
*
* Get the sequence number of the RTP packet in @buffer.
*
* Returns: The sequence number in host order.
*/
guint16
gst_rtp_buffer_get_seq (GstRTPBuffer * rtp)
{
return g_ntohs (GST_RTP_HEADER_SEQ (rtp->data[0]));
}
/**
* gst_rtp_buffer_set_seq:
* @rtp: the RTP packet
* @seq: the new sequence number
*
* Set the sequence number of the RTP packet in @buffer to @seq.
*/
void
gst_rtp_buffer_set_seq (GstRTPBuffer * rtp, guint16 seq)
{
GST_RTP_HEADER_SEQ (rtp->data[0]) = g_htons (seq);
}
/**
* gst_rtp_buffer_get_timestamp:
* @rtp: the RTP packet
*
* Get the timestamp of the RTP packet in @buffer.
*
* Returns: The timestamp in host order.
*/
guint32
gst_rtp_buffer_get_timestamp (GstRTPBuffer * rtp)
{
return g_ntohl (GST_RTP_HEADER_TIMESTAMP (rtp->data[0]));
}
/**
* gst_rtp_buffer_set_timestamp:
* @rtp: the RTP packet
* @timestamp: the new timestamp
*
* Set the timestamp of the RTP packet in @buffer to @timestamp.
*/
void
gst_rtp_buffer_set_timestamp (GstRTPBuffer * rtp, guint32 timestamp)
{
GST_RTP_HEADER_TIMESTAMP (rtp->data[0]) = g_htonl (timestamp);
}
/**
* gst_rtp_buffer_get_payload_subbuffer:
* @rtp: the RTP packet
* @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 is subbuffered.
*
* Returns: A new buffer with the specified data of the payload.
*/
GstBuffer *
gst_rtp_buffer_get_payload_subbuffer (GstRTPBuffer * rtp, guint offset,
guint len)
{
guint poffset, plen;
plen = gst_rtp_buffer_get_payload_len (rtp);
/* we can't go past the length */
if (G_UNLIKELY (offset > plen))
goto wrong_offset;
/* apply offset */
poffset = gst_rtp_buffer_get_header_len (rtp) + offset;
plen -= offset;
/* see if we need to shrink the buffer based on @len */
if (len != -1 && len < plen)
plen = len;
return gst_buffer_copy_region (rtp->buffer, GST_BUFFER_COPY_ALL, poffset,
plen);
/* ERRORS */
wrong_offset:
{
g_warning ("offset=%u should be less than plen=%u", offset, plen);
return NULL;
}
}
/**
* gst_rtp_buffer_get_payload_buffer:
* @rtp: the RTP packet
*
* 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.
*/
GstBuffer *
gst_rtp_buffer_get_payload_buffer (GstRTPBuffer * rtp)
{
return gst_rtp_buffer_get_payload_subbuffer (rtp, 0, -1);
}
/**
* gst_rtp_buffer_get_payload_len:
* @rtp: the RTP packet
*
* Get the length of the payload of the RTP packet in @buffer.
*
* Returns: The length of the payload in @buffer.
*/
guint
gst_rtp_buffer_get_payload_len (GstRTPBuffer * rtp)
{
return gst_buffer_get_size (rtp->buffer) - gst_rtp_buffer_get_header_len (rtp)
- rtp->size[3];
}
/**
* gst_rtp_buffer_get_payload: (skip)
* @rtp: the RTP packet
*
* Get a pointer to the payload data in @buffer. This pointer is valid as long
* as a reference to @buffer is held.
*
* Returns: (array) (element-type guint8) (transfer none): A pointer
* to the payload data in @buffer.
*/
gpointer
gst_rtp_buffer_get_payload (GstRTPBuffer * rtp)
{
if (rtp->data[2])
return rtp->data[2];
if (!gst_rtp_buffer_map_payload (rtp))
return NULL;
return rtp->data[2];
}
/**
* gst_rtp_buffer_get_payload_bytes: (rename-to gst_rtp_buffer_get_payload)
* @rtp: the RTP packet
*
* Similar to gst_rtp_buffer_get_payload, but more suitable for language
* bindings usage. The return value is a pointer to a #GBytes structure
* containing the payload data in @rtp.
*
* Returns: (transfer full): A new #GBytes containing the payload data in @rtp.
*
* Since: 1.2
*/
GBytes *
gst_rtp_buffer_get_payload_bytes (GstRTPBuffer * rtp)
{
gpointer data;
g_return_val_if_fail (rtp != NULL, NULL);
data = gst_rtp_buffer_get_payload (rtp);
if (data == NULL)
return NULL;
return g_bytes_new (data, gst_rtp_buffer_get_payload_len (rtp));
}
/**
* 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.
*/
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. This function
* returns the difference between @seqnum1 and @seqnum2.
*
* Returns: a negative value if @seqnum1 is bigger than @seqnum2, 0 if they
* are equal or a positive value if @seqnum1 is smaller than @segnum2.
*/
gint
gst_rtp_buffer_compare_seqnum (guint16 seqnum1, guint16 seqnum2)
{
/* See http://en.wikipedia.org/wiki/Serial_number_arithmetic
* for an explanation why this does the right thing even for
* wraparounds, under the assumption that the difference is
* never bigger than 2**15 sequence numbers
*/
return (gint16) (seqnum2 - seqnum1);
}
/**
* gst_rtp_buffer_ext_timestamp:
* @exttimestamp: (inout): a previous extended timestamp
* @timestamp: a new timestamp
*
* Update the @exttimestamp field with the extended timestamp of @timestamp
* For the first call of the method, @exttimestamp should point to a location
* with a value of -1.
*
* This function is able to handle both forward and backward timestamps taking
* into account:
* - timestamp wraparound making sure that the returned value is properly increased.
* - timestamp unwraparound making sure that the returned value is properly decreased.
*
* Returns: The extended timestamp of @timestamp or 0 if the result can't go anywhere backwards.
*/
guint64
gst_rtp_buffer_ext_timestamp (guint64 * exttimestamp, guint32 timestamp)
{
guint64 result, 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_GUINT64_CONSTANT (0xffffffff)));
/* check for timestamp wraparound */
if (result < ext) {
guint64 diff = ext - result;
if (diff > G_MAXINT32) {
/* timestamp went backwards more than allowed, we wrap around and get
* updated extended timestamp. */
result += (G_GUINT64_CONSTANT (1) << 32);
}
} else {
guint64 diff = result - ext;
if (diff > G_MAXINT32) {
if (result < (G_GUINT64_CONSTANT (1) << 32)) {
GST_WARNING
("Cannot unwrap, any wrapping took place yet. Returning 0 without updating extended timestamp.");
return 0;
} else {
/* timestamp went forwards more than allowed, we unwrap around and get
* updated extended timestamp. */
result -= (G_GUINT64_CONSTANT (1) << 32);
/* We don't want the extended timestamp storage to go back, ever */
return result;
}
}
}
}
*exttimestamp = result;
return result;
}
/**
* gst_rtp_buffer_get_extension_onebyte_header:
* @rtp: the RTP packet
* @id: The ID of the header extension to be read (between 1 and 14).
* @nth: Read the nth extension packet with the requested ID
* @data: (out) (array length=size) (element-type guint8) (transfer none):
* location for data
* @size: (out): the size of the data in bytes
*
* Parses RFC 5285 style header extensions with a one byte header. It will
* return the nth extension with the requested id.
*
* Returns: TRUE if @buffer had the requested header extension
*/
gboolean
gst_rtp_buffer_get_extension_onebyte_header (GstRTPBuffer * rtp, guint8 id,
guint nth, gpointer * data, guint * size)
{
guint16 bits;
guint8 *pdata;
guint wordlen;
gulong offset = 0;
guint count = 0;
g_return_val_if_fail (id > 0 && id < 15, FALSE);
if (!gst_rtp_buffer_get_extension_data (rtp, &bits, (gpointer) & pdata,
&wordlen))
return FALSE;
if (bits != 0xBEDE)
return FALSE;
for (;;) {
guint8 read_id, read_len;
if (offset + 1 >= wordlen * 4)
break;
read_id = GST_READ_UINT8 (pdata + offset) >> 4;
read_len = (GST_READ_UINT8 (pdata + offset) & 0x0F) + 1;
offset += 1;
/* ID 0 means its padding, skip */
if (read_id == 0)
continue;
/* ID 15 is special and means we should stop parsing */
if (read_id == 15)
break;
/* Ignore extension headers where the size does not fit */
if (offset + read_len > wordlen * 4)
break;
/* If we have the right one */
if (id == read_id) {
if (nth == count) {
if (data)
*data = pdata + offset;
if (size)
*size = read_len;
return TRUE;
}
count++;
}
offset += read_len;
if (offset >= wordlen * 4)
break;
}
return FALSE;
}
/**
* gst_rtp_buffer_get_extension_twobytes_header:
* @rtp: the RTP packet
* @appbits: (out): Application specific bits
* @id: The ID of the header extension to be read (between 1 and 14).
* @nth: Read the nth extension packet with the requested ID
* @data: (out) (array length=size) (element-type guint8) (transfer none):
* location for data
* @size: (out): the size of the data in bytes
*
* Parses RFC 5285 style header extensions with a two bytes header. It will
* return the nth extension with the requested id.
*
* Returns: TRUE if @buffer had the requested header extension
*/
gboolean
gst_rtp_buffer_get_extension_twobytes_header (GstRTPBuffer * rtp,
guint8 * appbits, guint8 id, guint nth, gpointer * data, guint * size)
{
guint16 bits;
guint8 *pdata = NULL;
guint wordlen;
guint bytelen;
gulong offset = 0;
guint count = 0;
if (!gst_rtp_buffer_get_extension_data (rtp, &bits, (gpointer *) & pdata,
&wordlen))
return FALSE;
if (bits >> 4 != 0x100)
return FALSE;
bytelen = wordlen * 4;
for (;;) {
guint8 read_id, read_len;
if (offset + 2 >= bytelen)
break;
read_id = GST_READ_UINT8 (pdata + offset);
offset += 1;
if (read_id == 0)
continue;
read_len = GST_READ_UINT8 (pdata + offset);
offset += 1;
/* Ignore extension headers where the size does not fit */
if (offset + read_len > bytelen)
break;
/* If we have the right one, return it */
if (id == read_id) {
if (nth == count) {
if (data)
*data = pdata + offset;
if (size)
*size = read_len;
if (appbits)
*appbits = bits;
return TRUE;
}
count++;
}
offset += read_len;
}
return FALSE;
}
static guint
get_onebyte_header_end_offset (guint8 * pdata, guint wordlen)
{
guint offset = 0;
guint bytelen = wordlen * 4;
guint paddingcount = 0;
while (offset + 1 < bytelen) {
guint8 read_id, read_len;
read_id = GST_READ_UINT8 (pdata + offset) >> 4;
read_len = (GST_READ_UINT8 (pdata + offset) & 0x0F) + 1;
offset += 1;
/* ID 0 means its padding, skip */
if (read_id == 0) {
paddingcount++;
continue;
}
paddingcount = 0;
/* ID 15 is special and means we should stop parsing */
/* It also means we can't add an extra packet */
if (read_id == 15)
return 0;
/* Ignore extension headers where the size does not fit */
if (offset + read_len > bytelen)
return 0;
offset += read_len;
}
return offset - paddingcount;
}
/**
* gst_rtp_buffer_add_extension_onebyte_header:
* @rtp: the RTP packet
* @id: The ID of the header extension (between 1 and 14).
* @data: (array length=size) (element-type guint8): location for data
* @size: the size of the data in bytes
*
* Adds a RFC 5285 header extension with a one byte header to the end of the
* RTP header. If there is already a RFC 5285 header extension with a one byte
* header, the new extension will be appended.
* It will not work if there is already a header extension that does not follow
* the mecanism described in RFC 5285 or if there is a header extension with
* a two bytes header as described in RFC 5285. In that case, use
* gst_rtp_buffer_add_extension_twobytes_header()
*
* Returns: %TRUE if header extension could be added
*/
gboolean
gst_rtp_buffer_add_extension_onebyte_header (GstRTPBuffer * rtp, guint8 id,
gconstpointer data, guint size)
{
guint16 bits;
guint8 *pdata = 0;
guint wordlen;
gboolean has_bit;
guint extlen, offset = 0;
g_return_val_if_fail (id > 0 && id < 15, FALSE);
g_return_val_if_fail (size >= 1 && size <= 16, FALSE);
g_return_val_if_fail (gst_buffer_is_writable (rtp->buffer), FALSE);
has_bit = gst_rtp_buffer_get_extension_data (rtp, &bits,
(gpointer) & pdata, &wordlen);
if (has_bit) {
if (bits != 0xBEDE)
return FALSE;
offset = get_onebyte_header_end_offset (pdata, wordlen);
if (offset == 0)
return FALSE;
}
/* the required size of the new extension data */
extlen = offset + size + 1;
/* calculate amount of words */
wordlen = extlen / 4 + ((extlen % 4) ? 1 : 0);
gst_rtp_buffer_set_extension_data (rtp, 0xBEDE, wordlen);
gst_rtp_buffer_get_extension_data (rtp, &bits, (gpointer) & pdata, &wordlen);
pdata += offset;
pdata[0] = (id << 4) | (0x0F & (size - 1));
memcpy (pdata + 1, data, size);
if (extlen % 4)
memset (pdata + 1 + size, 0, 4 - (extlen % 4));
return TRUE;
}
static guint
get_twobytes_header_end_offset (const guint8 * pdata, guint wordlen)
{
guint offset = 0;
guint bytelen = wordlen * 4;
guint paddingcount = 0;
while (offset + 2 < bytelen) {
guint8 read_id, read_len;
read_id = GST_READ_UINT8 (pdata + offset);
offset += 1;
/* ID 0 means its padding, skip */
if (read_id == 0) {
paddingcount++;
continue;
}
paddingcount = 0;
read_len = GST_READ_UINT8 (pdata + offset);
offset += 1;
/* Ignore extension headers where the size does not fit */
if (offset + read_len > bytelen)
return 0;
offset += read_len;
}
return offset - paddingcount;
}
/**
* gst_rtp_buffer_add_extension_twobytes_header:
* @rtp: the RTP packet
* @appbits: Application specific bits
* @id: The ID of the header extension
* @data: (array length=size) (element-type guint8): location for data
* @size: the size of the data in bytes
*
* Adds a RFC 5285 header extension with a two bytes header to the end of the
* RTP header. If there is already a RFC 5285 header extension with a two bytes
* header, the new extension will be appended.
* It will not work if there is already a header extension that does not follow
* the mecanism described in RFC 5285 or if there is a header extension with
* a one byte header as described in RFC 5285. In that case, use
* gst_rtp_buffer_add_extension_onebyte_header()
*
* Returns: %TRUE if header extension could be added
*/
gboolean
gst_rtp_buffer_add_extension_twobytes_header (GstRTPBuffer * rtp,
guint8 appbits, guint8 id, gconstpointer data, guint size)
{
guint16 bits;
guint8 *pdata = 0;
guint wordlen;
gboolean has_bit;
gulong offset = 0;
guint extlen;
g_return_val_if_fail ((appbits & 0xF0) == 0, FALSE);
g_return_val_if_fail (size < 256, FALSE);
g_return_val_if_fail (gst_buffer_is_writable (rtp->buffer), FALSE);
has_bit = gst_rtp_buffer_get_extension_data (rtp, &bits,
(gpointer) & pdata, &wordlen);
if (has_bit) {
if (bits != ((0x100 << 4) | (appbits & 0x0f)))
return FALSE;
offset = get_twobytes_header_end_offset (pdata, wordlen);
if (offset == 0)
return FALSE;
}
/* the required size of the new extension data */
extlen = offset + size + 2;
/* calculate amount of words */
wordlen = extlen / 4 + ((extlen % 4) ? 1 : 0);
gst_rtp_buffer_set_extension_data (rtp, (0x100 << 4) | (appbits & 0x0F),
wordlen);
gst_rtp_buffer_get_extension_data (rtp, &bits, (gpointer) & pdata, &wordlen);
pdata += offset;
pdata[0] = id;
pdata[1] = size;
memcpy (pdata + 2, data, size);
if (extlen % 4)
memset (pdata + 2 + size, 0, 4 - (extlen % 4));
return TRUE;
}