Module rtcp 

RTCP sender and receiver reports (RFC 3550 §6.4).

RTP carries the media; RTCP carries what happened to it. Without reports a stack cannot say why a call sounded bad, and cannot answer a peer that asks.

The field that repays attention is interarrival jitter. It is not a variance and not a standard deviation — it is the smoothed mean deviation of packet spacing, updated per packet by the RFC’s own recurrence:

J += (|D(i-1, i)| - J) / 16

An implementation that computes a variance instead produces numbers that look plausible, move in the right direction, and are wrong by a factor that depends on the traffic — which is worse than reporting nothing, because someone will tune a jitter buffer with them.

Structs

ReceiverReport

A receiver report: what we have received, from a participant that sends nothing.

ReportBlock

One report block: what one source’s stream looked like from here.

Sdes

A source description packet.

SdesChunk

What one source says about itself.

SdesItem

One source description item.

SenderReport

A sender report: what we have sent, plus what we have received from others.

StreamStats

Tracks what a stream looked like from here, so a report can be produced.

Enums

Rtcp

An RTCP packet.

RtcpError

What can go wrong reading RTCP.

Constants

GOODBYE

Goodbye.

RECEIVER_REPORT

A receiver report.

SDES_CNAME

The SDES item type of a canonical name (RFC 3550 §6.5.1).

SENDER_REPORT

RTCP packet types (RFC 3550 §12.1).

SOURCE_DESCRIPTION

A source description.