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Functions
rtcp.c File Reference

RTCP processing. More...

#include "debug.h"
#include "rtcp.h"
Include dependency graph for rtcp.c:

Functions

int janus_rtcp_parse (char *packet, int len)
 Method to parse/validate an RTCP message.
guint32 janus_rtcp_get_sender_ssrc (char *packet, int len)
 Method to quickly retrieve the sender SSRC (needed for demuxing RTCP in BUNDLE)
guint32 janus_rtcp_get_receiver_ssrc (char *packet, int len)
 Method to quickly retrieve the received SSRC (needed for demuxing RTCP in BUNDLE)
int janus_rtcp_fix_ssrc (char *packet, int len, int fixssrc, uint32_t newssrcl, uint32_t newssrcr)
 Method to fix an RTCP message (http://tools.ietf.org/html/draft-ietf-straw-b2bua-rtcp-00)
int janus_rtcp_has_fir (char *packet, int len)
 Method to check whether an RTCP message contains a FIR request.
int janus_rtcp_has_pli (char *packet, int len)
 Method to check whether an RTCP message contains a PLI request.
GSList * janus_rtcp_get_nacks (char *packet, int len)
 Method to parse an RTCP NACK message.
int janus_rtcp_remove_nacks (char *packet, int len)
 Method to remove an RTCP NACK message.
uint64_t janus_rtcp_get_remb (char *packet, int len)
 Inspect an existing RTCP REMB message to retrieve the reported bitrate.
int janus_rtcp_cap_remb (char *packet, int len, uint64_t bitrate)
 Method to modify an existing RTCP REMB message to cap the reported bitrate.
int janus_rtcp_sdes (char *packet, int len, const char *cname, int cnamelen)
 Method to generate a new RTCP SDES message.
int janus_rtcp_remb (char *packet, int len, uint64_t bitrate)
 Method to generate a new RTCP REMB message to cap the reported bitrate.
int janus_rtcp_fir (char *packet, int len, int *seqnr)
 Method to generate a new RTCP FIR message to request a key frame.
int janus_rtcp_fir_legacy (char *packet, int len, int *seqnr)
 Method to generate a new legacy RTCP FIR (RFC2032) message to request a key frame.
int janus_rtcp_pli (char *packet, int len)
 Method to generate a new RTCP PLI message to request a key frame.
int janus_rtcp_nacks (char *packet, int len, GSList *nacks)
 Method to generate a new RTCP NACK message to report lost packets.

Detailed Description

RTCP processing.

Author
Lorenzo Miniero loren.nosp@m.zo@m.nosp@m.eetec.nosp@m.ho.c.nosp@m.om

Implementation (based on the oRTP structures) of the RTCP messages. RTCP messages coming through the gateway are parsed and, if needed (according to http://tools.ietf.org/html/draft-ietf-straw-b2bua-rtcp-00), fixed before they are sent to the peers (e.g., to fix SSRCs that may have been changed by the gateway). Methods to generate FIR messages and generate/cap REMB messages are provided as well.

Protocols

Function Documentation

int janus_rtcp_cap_remb ( char *  packet,
int  len,
uint64_t  bitrate 
)

Method to modify an existing RTCP REMB message to cap the reported bitrate.

Parameters
[in]packetThe message data
[in]lenThe message data length in bytes
[in]bitrateThe new bitrate to report (e.g., 128000)
Returns
0 in case of success, -1 on errors
int janus_rtcp_fir ( char *  packet,
int  len,
int *  seqnr 
)

Method to generate a new RTCP FIR message to request a key frame.

Parameters
[in]packetThe buffer data (MUST be at least 20 chars)
[in]lenThe message data length in bytes (MUST be 20)
[in,out]seqnrThe current FIR sequence number (will be incremented by the method)
Returns
The message data length in bytes, if successful, -1 on errors
int janus_rtcp_fir_legacy ( char *  packet,
int  len,
int *  seqnr 
)

Method to generate a new legacy RTCP FIR (RFC2032) message to request a key frame.

Note
This is actually identical to janus_rtcp_fir(), with the difference that we set 192 as packet type
Parameters
[in]packetThe buffer data (MUST be at least 20 chars)
[in]lenThe message data length in bytes (MUST be 20)
[in,out]seqnrThe current FIR sequence number (will be incremented by the method)
Returns
The message data length in bytes, if successful, -1 on errors
int janus_rtcp_fix_ssrc ( char *  packet,
int  len,
int  fixssrc,
uint32_t  newssrcl,
uint32_t  newssrcr 
)

Method to fix an RTCP message (http://tools.ietf.org/html/draft-ietf-straw-b2bua-rtcp-00)

Parameters
[in]packetThe message data
[in]lenThe message data length in bytes
[in]fixssrcWhether the method needs to fix the message or just parse it
[in]newssrclThe SSRC of the sender to put in the message
[in]newssrcrThe SSRC of the receiver to put in the message
Returns
0 in case of success, -1 on errors
GSList* janus_rtcp_get_nacks ( char *  packet,
int  len 
)

Method to parse an RTCP NACK message.

Parameters
[in]packetThe message data
[in]lenThe message data length in bytes
Returns
A list of janus_nack elements containing the sequence numbers to send again
guint32 janus_rtcp_get_receiver_ssrc ( char *  packet,
int  len 
)

Method to quickly retrieve the received SSRC (needed for demuxing RTCP in BUNDLE)

Parameters
[in]packetThe message data
[in]lenThe message data length in bytes
Returns
The receiver SSRC, or 0 in case of error
uint64_t janus_rtcp_get_remb ( char *  packet,
int  len 
)

Inspect an existing RTCP REMB message to retrieve the reported bitrate.

Parameters
[in]packetThe message data
[in]lenThe message data length in bytes
Returns
The reported bitrate if successful, 0 if no REMB packet was available
guint32 janus_rtcp_get_sender_ssrc ( char *  packet,
int  len 
)

Method to quickly retrieve the sender SSRC (needed for demuxing RTCP in BUNDLE)

Parameters
[in]packetThe message data
[in]lenThe message data length in bytes
Returns
The sender SSRC, or 0 in case of error
int janus_rtcp_has_fir ( char *  packet,
int  len 
)

Method to check whether an RTCP message contains a FIR request.

Parameters
[in]packetThe message data
[in]lenThe message data length in bytes
Returns
TRUE in case of success, FALSE otherwise
int janus_rtcp_has_pli ( char *  packet,
int  len 
)

Method to check whether an RTCP message contains a PLI request.

Parameters
[in]packetThe message data
[in]lenThe message data length in bytes
Returns
TRUE in case of success, FALSE otherwise
int janus_rtcp_nacks ( char *  packet,
int  len,
GSList *  nacks 
)

Method to generate a new RTCP NACK message to report lost packets.

Parameters
[in]packetThe buffer data (MUST be at least 16 chars)
[in]lenThe message data length in bytes (MUST be 16)
[in]nacksList of packets to NACK
Returns
The message data length in bytes, if successful, -1 on errors
int janus_rtcp_parse ( char *  packet,
int  len 
)

Method to parse/validate an RTCP message.

Parameters
[in]packetThe message data
[in]lenThe message data length in bytes
Returns
0 in case of success, -1 on errors
int janus_rtcp_pli ( char *  packet,
int  len 
)

Method to generate a new RTCP PLI message to request a key frame.

Parameters
[in]packetThe buffer data (MUST be at least 12 chars)
[in]lenThe message data length in bytes (MUST be 12)
Returns
The message data length in bytes, if successful, -1 on errors
int janus_rtcp_remb ( char *  packet,
int  len,
uint64_t  bitrate 
)

Method to generate a new RTCP REMB message to cap the reported bitrate.

Parameters
[in]packetThe buffer data (MUST be at least 24 chars)
[in]lenThe message data length in bytes (MUST be 24)
[in]bitrateThe bitrate to report (e.g., 128000)
Returns
The message data length in bytes, if successful, -1 on errors
int janus_rtcp_remove_nacks ( char *  packet,
int  len 
)

Method to remove an RTCP NACK message.

Parameters
[in]packetThe message data
[in]lenThe message data length in bytes
Returns
The new message data length in bytes
Note
This is mostly a placeholder: for the sake of simplicity, whenever we handle some sequence numbers in a NACK, we remove the NACK as a whole before forwarding the RTCP message. Future versions will only selectively remove the sequence numbers that have been handled.
int janus_rtcp_sdes ( char *  packet,
int  len,
const char *  cname,
int  cnamelen 
)

Method to generate a new RTCP SDES message.

Parameters
[in]packetThe buffer data
[in]lenThe buffer data length in bytes
[in]cnameThe CNAME to write
[in]cnamelenThe CNAME data length in bytes
Returns
The message data length in bytes, if successful, -1 on errors