broadcast-loudness

EBU R 128 / ITU-R BS.1770-5 loudness measurement for Rust.

K-weighting filter, integrated/short-term/momentary loudness (LUFS), Loudness Range (LRA, LU), and true-peak level (dBTP).

no_std + alloc, depends only on broadcast-common.

Quick start

use broadcast_loudness::{ChannelLayout, LoudnessMeter};

let mut meter = LoudnessMeter::new(48_000, ChannelLayout::Stereo).unwrap();
meter.push_interleaved_f32(&left_samples, &right_samples).unwrap();
meter.finish();

println!("Integrated: {:.1} LUFS", meter.integrated_lufs());
println!("LRA:       {:.1} LU",   meter.loudness_range());
println!("Max M:     {:.1} LUFS", meter.max_momentary_lufs());
println!("Max S:     {:.1} LUFS", meter.max_short_term_lufs());

Features

• K-weighting filter — exact BS.1770-5 Annex 1 biquad coefficients (48 kHz)
• Channel weighting — Table 3 G_i weights (mono, stereo, 5.1, custom)
• Gating — absolute (−70 LUFS) and relative (−10 LU) per BS.1770-5 Annex 1
• Three time scales — momentary (400 ms), short-term (3 s), integrated (gated)
• Loudness Range (LRA) — EBU Tech 3342 percentile-based
• True-peak — 4× oversampling, 48-tap polyphase FIR (BS.1770-5 Annex 2)
• no_std + alloc — runs on bare-metal (thumbv7em-none-eabi)

Compliance

Passes EBU Tech 3341 minimum-requirements compliance tests (cases 1–6, 9, 11, 15–19) and EBU Tech 3342 LRA tests (cases 1–3). Spec citations in docs/.

ATSC A/85 is out of scope. Only 48 kHz input is supported (the K-weighting coefficients in BS.1770-5 are tabulated only for 48 kHz).

License

MIT OR Apache-2.0