RustyOpus

Pure-Rust Opus for Elixir. No C libopus, no ffmpeg, no external process — shrink real Ogg Opus blobs (or work with raw packets/PCM) in one BEAM process.

Headline: take an Ogg Opus file/blob and make it smaller with a numeric bitrate (defaults: VoIP, complexity 10, VBR, 20 ms — FFmpeg speech ladder analogues):

{:ok, smaller} = RustyOpus.reencode(ogg_blob, bitrate: 20_000)

That is the whole call. Useful bitrate ladder values: 8_000, 12_000, 16_000, 20_000, 24_000, 32_000.

Quick start

# Ogg Opus blob → smaller Ogg Opus blob (default path for files)
{:ok, smaller} = RustyOpus.reencode(ogg_blob, bitrate: 20_000)

# Raw packets / PCM (no container)
{:ok, packets} = RustyOpus.encode(pcm, 16_000, 1, bitrate: 24_000)
{:ok, pcm}     = RustyOpus.decode(packets, 16_000, 1)

Data contract

• Ogg Opus — RFC 7845 binaries (audio/ogg / .ogg) for reencode/2.
• PCM — little-endian IEEE-754 f32, interleaved for stereo.
• Opus packets — raw binaries (no container).

No WebM/MP4. Never launches an external process. See the codec guide.

Features

• RustyOpus.reencode/2 — Ogg Opus blob → lower bitrate Ogg Opus blob (opus-rs + thin Ogg)
• RustyOpus.encode/4, decode/4, transcode/5 — whole-stream raw packet/PCM path
• RustyOpus.Encoder / Decoder — per-frame control
• Dirty-scheduled codec work; panic containment at the NIF boundary
• Checksum-verified precompiled NIFs with source-build fallback

Supported OS

Precompiled NIFs are published for:

• Apple Silicon macOS (aarch64-apple-darwin)
• Intel macOS (x86_64-apple-darwin)
• ARM64 Linux glibc (aarch64-unknown-linux-gnu)
• ARM64 Linux musl / Alpine (aarch64-unknown-linux-musl)
• x86-64 Linux glibc (x86_64-unknown-linux-gnu)
• x86-64 Linux musl / Alpine (x86_64-unknown-linux-musl)

Other targets can build from source with RUSTY_OPUS_BUILD=1 and Rust 1.89.0.

Technology

Development

bin/qa_check.sh

Committed fixtures include an Ogg Opus speech blob for reencode/2 tests. Tests need neither a live database nor ffmpeg.

Release

1. Bump the version in mix.exs and native/rusty_opus_native/Cargo.toml.
2. Run bin/qa_check.sh and push the green version commit.
3. Tag v0.3.3; the release workflow builds and smoke-tests every precompiled NIF.
4. Publish the Hex package and GitHub release (maintainer step).

License

RustyOpus is licensed under the Apache License 2.0. Bundled codec: opus-rs (BSD-3-Clause) — see NOTICE and provenance.