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RTP 
 
 
Real-Time Transport Protocol (RTP) Implementation. 
 
 
 
 
The Real-Time Transport Protocol (RTP) is a protocol for the transport 
of audio, video, and other real-time data across IP capable networks. 
 
 
 
 
 
 
   
    RFC1889 - RTP: A Transport Protocol for Real-Time Applications  
    
 
   
    RFC1890 - RTP Profile for Audio and Video Conferences with Minimal Control  
   
 
   
      IETF Audio/Video Transport Group 
   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
The struct begins with pointers to the data in the packet as 
it came off the wire. The packet is read in such that the 
header maps onto the latter part of this struct, and the 
fields in this first part of the struct point into it. The 
entire packet can be freed by freeing this struct, without 
having to free the csrc, data and extn blocks separately. 
WARNING: Don't change the size of the first portion of the 
struct without changing RTP_PACKET_HEADER_SIZE to match. 
 
 
 
 
 
This macro MUST resolve to the offset of the first packet 
field in the #rtp_packet struct, including all padding. 
If you change rtp_packet, make sure to change this too. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Possible values of Session Description (SDES) identifiers.  SDES items 
are announced via #rtp_callback (with RX_SDES events) when they are 
received.  SDES items may be configured and queried with #rtp_set_sdes 
and #rtp_get_sdes.  The RTP guidelines recommend keeping SDES items 
constant during an RTP session to avoid confusing end users. 
 
 
@RTCP_SDES_END: Indicates the end of SDES item processing when SDES data is received.  Has no meaning with #rtp_set_sdes and #rtp_get_sdes. 
@RTCP_SDES_CNAME: The canonical name associated with participant. It is algorithmically derived and should never be changed. 
@RTCP_SDES_NAME: The local participant's name, typically displayed in RTP session participant list. The name can take any form, and should remain constant during a session to avoid confusion. 
@RTCP_SDES_EMAIL: The local participant's email address (optional). 
@RTCP_SDES_PHONE: The local participant's telephone number (optional). 
@RTCP_SDES_LOC: The local participant's geographic location (optional). 
@RTCP_SDES_TOOL: The local participant's tool (optional). 
@RTCP_SDES_NOTE: Any additional information the local participant wishes to communicate about themselves (optional). 
@RTCP_SDES_PRIV: Private extension SDES item see RFC1889 for details. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
This callback function crafts an RTCP APP packet to be sent with 
an RTCP RR. 
 
 
@session: the session pointer (returned by rtp_init()) 
@rtp_ts: the current time expressed in units of the media timestamp. 
@max_size: the max allowed size of an APP packet. 
@Returns: A fully-formed RTCP APP packet as an #rtcp_app, or NULL (???) 
if no APP packet needs to be sent at this time. 
 
 
 
 
The possible values for the type field in #rtp_event. 
Each value represents an event in RTP or RTCP processing. 
 
 
@RX_RTP: An RTP data packet was received. 
The ssrc field contains the RTP data packet's SSRC. 
The data field points to a #rtp_packet containing the RTP data packet. 
The callback must free the rtp_packet when it's done with it using the xfree() function. 
@RX_SR: An RTCP SR packet was received. 
The ssrc field contains the SR packet's SSRC. 
The data field points to an #rtcp_sr. 
@RX_RR: An RTCP RR packet was received. 
The ssrc field contains the RR packet's SSRC. 
The data field points to an #rtcp_rr. 
@RX_SDES: An RTCP SDES packet was received. 
The ssrc field contains the SDES packet's SSRC. 
The data field points to an #rtcp_sdes_item. 
@RX_BYE: An RTCP BYE packet was received. 
The ssrc field contains the BYE packet's SSRC. 
@SOURCE_CREATED: A new session participant was heard from. 
The ssrc field contains the new participant's SSRC. 
@SOURCE_DELETED: A source was deleted from the database. 
The ssrc field contains the ex-participant's SSRC. 
@RX_RR_EMPTY: An RTCP RR packet with no sources listed was received. 
The ssrc field contains the RR packet's SSRC. 
@RX_RTCP_START: Called at the start of parsing an RTCP packet. 
Neither the ssrc nor data fields are valid. 
@RX_RTCP_FINISH: Called at the end of parsing an RTCP packet. 
Neither the ssrc nor data fields are valid. 
@RR_TIMEOUT: An RR from the given receiver has not been refreshed recently enough. 
The ssrc field contains the RR packet's SSRC. 
The data field points to the expiring #rtcp_rr. 
@RX_APP: An APP packet was received. 
The ssrc field contains the APP packet's SSRC. 
The data field points to an #rtcp_app. 
The callback must free the app packet when it's done with it. 
 
 
 
The event structure as passed to rtp_callback(). 
The callback type is carried in the type field; see #rtp_event_type 
for a description of each callback. 
Unless otherwise noted, the ssrc field contains the SSRC of the participant 
triggering this callback.  The data field points to any data contained in 
this callback; it must be cast to the appropriate type.  The ts field 
contains the timestamp of the packet reception that caused this event. 
 
 
 
 
 
Handles RTP events in an application-specific way. 
See #rtp_event for a description of the possible events and 
how rtp_callback() should handle each. 
 
 
 
@session: The RTP Session. 
@e: The RTP Event information.  See #rtp_event. 
 
 
 
 
The possible options for a session that affect which RTP packets are 
passed to the application and when internal state for sources is created. 
 
 
@RTP_OPT_PROMISC: Pass RTP packets to application irrespective of 
whether a sender report has been received.  Normally, participant 
state is created when a sender report is received and RTP packets that 
arrive prior to the sender report are discarded. 
@RTP_OPT_WEAK_VALIDATION: Create source state when RTP packets arrive 
if none exists.  This option is set by default.  Disabling the option 
means source state is only created when sender reports are received. 
@RTP_OPT_FILTER_MY_PACKETS: Filter out packets from local participant 
if they are received.  With multicast sessions, packets may be looped 
back, causing senders packets to be received locally.  This may be 
filtered out with this option. 
 
 
 
 
 
 
@addr:  
@rx_port:  
@tx_port:  
@ttl:  
@rtcp_bw:  
@callback:  
@userdata:  
@Returns:  
 
 
 
 
 
 
 
@addr:  
@iface:  
@rx_port:  
@tx_port:  
@ttl:  
@rtcp_bw:  
@callback:  
@userdata:  
@Returns:  
 
 
 
 
 
 
 
@session:  
 
 
 
 
 
 
 
@session:  
 
 
 
 
 
 
 
@session:  
@optname:  
@optval:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@optname:  
@optval:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@timeout:  
@curr_rtp_ts:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@rtp_ts:  
@pt:  
@m:  
@cc:  
@csrc:  
@data:  
@data_len:  
@extn:  
@extn_len:  
@extn_type:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@rtp_ts:  
@appcallback:  
 
 
 
 
 
 
 
@session:  
 
 
 
 
 
 
 
@session:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@csrc:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@csrc:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@ssrc:  
@type:  
@value:  
@length:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@ssrc:  
@type:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@ssrc:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@reporter:  
@reportee:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@passphrase:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@ssrc:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@Returns:  
 
 
 
 
 
 
 
@session:  
@Returns: