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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.
Last reviewed on 2006-07-17 (0.10.10)
void gst_rtp_buffer_allocate_data (GstBuffer *buffer
,guint payload_len
,guint8 pad_len
,guint8 csrc_count
);
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.
GstBuffer * gst_rtp_buffer_new_take_data (gpointer data
,guint len
);
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.
GstBuffer * gst_rtp_buffer_new_copy_data (gpointer data
,guint len
);
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.
GstBuffer * gst_rtp_buffer_new_allocate (guint payload_len
,guint8 pad_len
,guint8 csrc_count
);
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.
GstBuffer * gst_rtp_buffer_new_allocate_len (guint packet_len
,guint8 pad_len
,guint8 csrc_count
);
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.
GstBufferList *
gst_rtp_buffer_list_from_buffer (GstBuffer *buffer
);
Splits a GstBuffer into a GstBufferList containing separate buffers for the header and data sections.
guint
gst_rtp_buffer_calc_header_len (guint8 csrc_count
);
Calculate the header length of an RTP packet with csrc_count
CSRC entries.
An RTP packet can have at most 15 CSRC entries.
guint gst_rtp_buffer_calc_packet_len (guint payload_len
,guint8 pad_len
,guint8 csrc_count
);
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.
guint gst_rtp_buffer_calc_payload_len (guint packet_len
,guint8 pad_len
,guint8 csrc_count
);
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.
gboolean
gst_rtp_buffer_validate (GstBuffer *buffer
);
Check if the data pointed to by buffer
is a valid RTP packet using
gst_rtp_buffer_validate_data()
.
Use this function to validate a packet before using the other functions in
this module.
gboolean gst_rtp_buffer_validate_data (guint8 *data
,guint len
);
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.
void gst_rtp_buffer_set_packet_len (GstBuffer *buffer
,guint len
);
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.
guint
gst_rtp_buffer_get_packet_len (GstBuffer *buffer
);
Return the total length of the packet in buffer
.
guint
gst_rtp_buffer_get_header_len (GstBuffer *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.
guint8
gst_rtp_buffer_get_version (GstBuffer *buffer
);
Get the version number of the RTP packet in buffer
.
void gst_rtp_buffer_set_version (GstBuffer *buffer
,guint8 version
);
Set the version of the RTP packet in buffer
to version
.
gboolean
gst_rtp_buffer_get_padding (GstBuffer *buffer
);
Check if the padding bit is set on the RTP packet in buffer
.
void gst_rtp_buffer_set_padding (GstBuffer *buffer
,gboolean padding
);
Set the padding bit on the RTP packet in buffer
to padding
.
void gst_rtp_buffer_pad_to (GstBuffer *buffer
,guint len
);
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.
gboolean
gst_rtp_buffer_get_extension (GstBuffer *buffer
);
Check if the extension bit is set on the RTP packet in buffer
.
void gst_rtp_buffer_set_extension (GstBuffer *buffer
,gboolean extension
);
Set the extension bit on the RTP packet in buffer
to extension
.
gboolean gst_rtp_buffer_get_extension_data (GstBuffer *buffer
,guint16 *bits
,gpointer *data
,guint *wordlen
);
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.
buffer |
the buffer |
|
bits |
location for result bits |
|
data |
location for data |
|
wordlen |
location for length of |
Since 0.10.15
guint32
gst_rtp_buffer_get_ssrc (GstBuffer *buffer
);
Get the SSRC of the RTP packet in buffer
.
void gst_rtp_buffer_set_ssrc (GstBuffer *buffer
,guint32 ssrc
);
Set the SSRC on the RTP packet in buffer
to ssrc
.
guint8
gst_rtp_buffer_get_csrc_count (GstBuffer *buffer
);
Get the CSRC count of the RTP packet in buffer
.
guint32 gst_rtp_buffer_get_csrc (GstBuffer *buffer
,guint8 idx
);
Get the CSRC at index idx
in buffer
.
void gst_rtp_buffer_set_csrc (GstBuffer *buffer
,guint8 idx
,guint32 csrc
);
Modify the CSRC at index idx
in buffer
to csrc
.
gboolean
gst_rtp_buffer_get_marker (GstBuffer *buffer
);
Check if the marker bit is set on the RTP packet in buffer
.
void gst_rtp_buffer_set_marker (GstBuffer *buffer
,gboolean marker
);
Set the marker bit on the RTP packet in buffer
to marker
.
guint8
gst_rtp_buffer_get_payload_type (GstBuffer *buffer
);
Get the payload type of the RTP packet in buffer
.
void gst_rtp_buffer_set_payload_type (GstBuffer *buffer
,guint8 payload_type
);
Set the payload type of the RTP packet in buffer
to payload_type
.
guint16
gst_rtp_buffer_get_seq (GstBuffer *buffer
);
Get the sequence number of the RTP packet in buffer
.
void gst_rtp_buffer_set_seq (GstBuffer *buffer
,guint16 seq
);
Set the sequence number of the RTP packet in buffer
to seq
.
guint32
gst_rtp_buffer_get_timestamp (GstBuffer *buffer
);
Get the timestamp of the RTP packet in buffer
.
void gst_rtp_buffer_set_timestamp (GstBuffer *buffer
,guint32 timestamp
);
Set the timestamp of the RTP packet in buffer
to timestamp
.
GstBuffer *
gst_rtp_buffer_get_payload_buffer (GstBuffer *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.
GstBuffer * gst_rtp_buffer_get_payload_subbuffer (GstBuffer *buffer
,guint offset
,guint len
);
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.
Since 0.10.10
guint
gst_rtp_buffer_get_payload_len (GstBuffer *buffer
);
Get the length of the payload of the RTP packet in buffer
.
gpointer
gst_rtp_buffer_get_payload (GstBuffer *buffer
);
Get a pointer to the payload data in buffer
. This pointer is valid as long
as a reference to buffer
is held.
guint32
gst_rtp_buffer_default_clock_rate (guint8 payload_type
);
Get the default clock-rate for the static payload type payload_type
.
the default clock rate or -1 if the payload type is not static or the clock-rate is undefined.
Since 0.10.13
gint gst_rtp_buffer_compare_seqnum (guint16 seqnum1
,guint16 seqnum2
);
Compare two sequence numbers, taking care of wraparounds. This function
returns the difference between seqnum1
and seqnum2
.
a negative value if seqnum1
is bigger than seqnum2
, 0 if they
are equal or a positive value if seqnum1
is smaller than segnum2
.
Since 0.10.15
guint64 gst_rtp_buffer_ext_timestamp (guint64 *exttimestamp
,guint32 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.
Since 0.10.15
gboolean gst_rtp_buffer_set_extension_data (GstBuffer *buffer
,guint16 bits
,guint16 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.
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) |
Since 0.10.18
gboolean
gst_rtp_buffer_list_validate (GstBufferList *list
);
Check if all RTP packets in the list
are valid using gst_rtp_buffer_validate_data()
.
Use this function to validate an list before using the other functions in
this module.
Since 0.10.24
guint
gst_rtp_buffer_list_get_payload_len (GstBufferList *list
);
Get the length of the payload of the RTP packet in list
.
Since 0.10.24
guint8
gst_rtp_buffer_list_get_payload_type (GstBufferList *list
);
Get the payload type of the first RTP packet in list
.
All packets in list
should have the same payload type.
Since 0.10.24
void gst_rtp_buffer_list_set_payload_type (GstBufferList *list
,guint8 payload_type
);
Set the payload type of each RTP packet in list
to payload_type
.
Since 0.10.24
guint16
gst_rtp_buffer_list_get_seq (GstBufferList *list
);
Get the sequence number of the first RTP packet in list
.
All packets within list
have the same sequence number.
Since 0.10.24
guint16 gst_rtp_buffer_list_set_seq (GstBufferList *list
,guint16 seq
);
Set the sequence number of each RTP packet in list
to seq
.
Since 0.10.24
guint32
gst_rtp_buffer_list_get_ssrc (GstBufferList *list
);
Get the SSRC of the first RTP packet in list
.
All RTP packets within list
have the same SSRC.
Since 0.10.24
void gst_rtp_buffer_list_set_ssrc (GstBufferList *list
,guint32 ssrc
);
Set the SSRC on each RTP packet in list
to ssrc
.
Since 0.10.24
guint32
gst_rtp_buffer_list_get_timestamp (GstBufferList *list
);
Get the timestamp of the first RTP packet in list
.
All packets within list
have the same timestamp.
Since 0.10.24
void gst_rtp_buffer_list_set_timestamp (GstBufferList *list
,guint32 timestamp
);
Set the timestamp of each RTP packet in list
to timestamp
.
Since 0.10.24
gboolean gst_rtp_buffer_get_extension_onebyte_header (GstBuffer *buffer
,guint8 id
,guint nth
,gpointer *data
,guint *size
);
Parses RFC 5285 style header extensions with a one byte header. It will return the nth extension with the requested id.
buffer |
the buffer |
|
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 |
location for data |
|
size |
the size of the data in bytes |
Since 0.10.31
gboolean gst_rtp_buffer_get_extension_twobytes_header (GstBuffer *buffer
,guint8 *appbits
,guint8 id
,guint nth
,gpointer *data
,guint *size
);
Parses RFC 5285 style header extensions with a two bytes header. It will return the nth extension with the requested id.
buffer |
the buffer |
|
appbits |
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 |
location for data |
|
size |
the size of the data in bytes |
Since 0.10.31
gboolean gst_rtp_buffer_add_extension_onebyte_header (GstBuffer *buffer
,guint8 id
,gpointer data
,guint size
);
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()
buffer |
the buffer |
|
id |
The ID of the header extension (between 1 and 14). |
|
data |
location for data |
|
size |
the size of the data in bytes |
Since 0.10.31
gboolean gst_rtp_buffer_add_extension_twobytes_header (GstBuffer *buffer
,guint8 appbits
,guint8 id
,gpointer data
,guint size
);
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()
buffer |
the buffer |
|
appbits |
Application specific bits |
|
id |
The ID of the header extension |
|
data |
location for data |
|
size |
the size of the data in bytes |
Since 0.10.31
gboolean gst_rtp_buffer_list_get_extension_onebyte_header (GstBufferList *bufferlist
,guint group_idx
,guint8 id
,guint nth
,gpointer *data
,guint *size
);
Parses RFC 5285 style header extensions with a one byte header. It will return the nth extension with the requested id.
bufferlist |
the bufferlist |
|
group_idx |
The index of the group in the GstBufferList |
|
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 |
location for data |
|
size |
the size of the data in bytes |
Since 0.10.31
gboolean gst_rtp_buffer_list_get_extension_twobytes_header (GstBufferList *bufferlist
,guint group_idx
,guint8 *appbits
,guint8 id
,guint nth
,gpointer *data
,guint *size
);
Parses RFC 5285 style header extensions with a two bytes header. It will return the nth extension with the requested id.
bufferlist |
the bufferlist |
|
group_idx |
The index of the group in the GstBufferList |
|
appbits |
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 |
location for data |
|
size |
the size of the data in bytes |
Since 0.10.31
gboolean gst_rtp_buffer_list_add_extension_onebyte_header (GstBufferListIterator *it
,guint8 id
,gpointer data
,guint size
);
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_list_add_extension_twobytes_header()
This function will not modify the data section of the RTP buffer, only the header.
it |
a GstBufferListIterator pointing right after the GstBuffer where the header extension should be added |
|
id |
The ID of the header extension (between 1 and 14). |
|
data |
location for data |
|
size |
the size of the data in bytes |
Since 0.10.31
gboolean gst_rtp_buffer_list_add_extension_twobytes_header (GstBufferListIterator *it
,guint8 appbits
,guint8 id
,gpointer data
,guint size
);
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()
This function will not modify the data section of the RTP buffer, only the header.
it |
a GstBufferListIterator pointing right after the GstBuffer where the header extension should be added |
|
appbits |
Application specific bits |
|
id |
The ID of the header extension |
|
data |
location for data |
|
size |
the size of the data in bytes |
Since 0.10.31