rdd29

SMPTE RDD 29:2019 ("Dolby Atmos® Bitstream Specification") frame/element framing plus bed/object rendering metadata — no_std.

RDD 29 defines a frame-based bitstream carrying, per frame, a single ATMOSFrame element containing:

[BedDefinition1] — a channel-based audio bed's channel-to-audio-asset mapping (§2.2/§4.3): which loudspeaker each channel plays to, and which AudioDataDLC element carries its audio.
[ObjectDefinition1] — one panned audio object's per-sub-block rendering metadata (§2.3/§4.4): 3D position, snap-to-speaker, per-zone gain, spread, decorrelation, and an optional text description.
[AudioDataDlc] — one track's audio-essence pointer + opaque payload (§2.4/§4.5).

See docs/rdd29.md for the curated SMPTE RDD 29:2019 §1-§5 transcription this crate implements field-for-field (fetched directly from pub.smpte.org/pub/rdd29/rdd29-2019.pdf), including the "Scope decisions" section documenting two genuine gaps/inconsistencies in the source disclosure document itself (the Plex(8) escape-nesting pseudocode's internal inconsistency, and the undocumented AudioDescription field semantics) and how this crate resolves each honestly.

What this crate is not: an audio codec. AudioDataDlc's payload is the Dolby Lossless Coding (DLC) codec's own bit-packed bitstream (linear- predictive + Rice-Golomb entropy-coded residual audio samples) — this crate treats it as opaque bytes, the same "parse the container, not the codec" discipline this workspace's transmux/st337 crates use for media containers and AES3 non-PCM bursts respectively.

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

Quick start

use broadcast_common::{Parse, Serialize};
use rdd29::{AtmosFrame, AudioDataDlc, BedChannel, BedDefinition1, BitDepth, ChannelId, FrameRate, SampleRate};

let bed = BedDefinition1::new(1, vec![BedChannel { channel_id: ChannelId::LeftScreen, audio_data_id: 10 }]);
let dlc = AudioDataDlc::new(10, &[0xDE, 0xAD, 0xBE, 0xEF]).unwrap();

let frame = AtmosFrame::new(
    SampleRate::Hz48000,
    BitDepth::Bits24,
    FrameRate::Fps24,
    1,
    vec![rdd29::AnyElement::BedDefinition1(bed), rdd29::AnyElement::AudioDataDlc(dlc)],
);

let bytes = frame.to_bytes();
assert_eq!(AtmosFrame::parse(&bytes).unwrap(), frame);

Examples

cargo run -p rdd29 --example build_atmos_frame
cargo run -p rdd29 --example parse_atmos_frame

Features

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

Minimum Supported Rust Version

1.86

License