rtcp-packet

RFC 3550 §6 RTCP control packets — SR, RR, SDES, BYE, APP, and the §6.1 compound packet — spec-complete parse/serialize, no_std.

rtcp-packet is a shared low-level wire crate (in the same spirit as rtp-packet/mpeg-ts/mpeg-pes/mpeg-ps): a single, spec-complete implementation of the RTCP control-packet codec meant to be consumed by every higher-level crate that speaks RTP/RTCP (transmux's RTCP module today), instead of each crate re-implementing its own codec. It was extracted unchanged from transmux::rtcp.

[SenderReport] (SR, §6.4.1, PT 200) / [ReceiverReport] (RR, §6.4.2, PT 201) / [ReportBlock] — the shared 24-byte reception report block, including the §6.4.1 24-bit signed cumulative_lost.
[SourceDescription] / [SdesChunk] / [SdesItem] / [SdesItemType] (SDES, §6.5, PT 202) — CNAME/NAME/EMAIL/PHONE/LOC/ TOOL/NOTE/PRIV item types, 32-bit chunk padding.
[Bye] (§6.6, PT 203) — SSRC/CSRC list + optional reason text.
[App] (§6.7, PT 204) — subtype, SSRC, 4-byte ASCII name, application-dependent data.
[RtcpPacket] / [RtcpPacketType] — the PT-byte dispatch enum.
[CompoundPacket] (§6.1) — a sequence of RTCP packets that must begin with SR or RR, with byte-exact round-trip across the whole compound.

See docs/rtcp.md for the curated RFC 3550 §6 transcription this crate implements field-for-field, including two documented decode-completeness gaps (SR/RR profile-specific extensions; the SDES PRIV item's internal prefix/value sub-structure) that are not separately typed.

#![no_std] + alloc; depends only on broadcast-common.

Quick start

use broadcast_common::{Parse, Serialize};
use rtcp_packet::{ReportBlock, SenderReport};

let sr = SenderReport {
    ssrc: 0x1122_3344,
    ntp_msw: 0xE0E1_E2E3,
    ntp_lsw: 0x1020_3040,
    rtp_timestamp: 0x0009_0000,
    packet_count: 4321,
    octet_count: 999_999,
    report_blocks: vec![ReportBlock {
        ssrc: 0xAAAA_AAAA,
        fraction_lost: 12,
        cumulative_lost: -3,
        ext_highest_seq: 0x0001_2345,
        jitter: 500,
        lsr: 0xAABB_CCDD,
        dlsr: 0x0000_1000,
    }],
};
let mut bytes = vec![0u8; sr.serialized_len()];
sr.serialize_into(&mut bytes).unwrap();
assert_eq!(SenderReport::parse(&bytes).unwrap(), sr);

Examples

cargo run -p rtcp-packet --example build_sender_report
cargo run -p rtcp-packet --example parse_compound_packet

Features

Feature	Default	Description
`std`	yes	Link the standard library. Without it the crate is `#![no_std]` + `alloc`.
`serde`	no	`serde::Serialize` derives on public types.

Minimum Supported Rust Version

1.86

License