oximedia-audio

Audio codec implementations and DSP tools for the OxiMedia multimedia framework.

Part of the oximedia workspace — a comprehensive pure-Rust media processing framework.

Version: 0.2.1 — 2026-08-12 — extensively tested

Overview

oximedia-audio provides encoding and decoding for royalty-free audio codecs, plus a comprehensive suite of DSP, effects, metering, spatial audio, and analysis tools.

Features

Codec Support

Enable specific codecs via Cargo features (all enabled by default):

[dependencies]
oximedia-audio = { version = "0.2.0", features = ["opus", "vorbis", "flac", "mp3"] }

DSP

The dsp module provides standalone digital signal processing:

• Biquad Filters — Second-order IIR filters
• Parametric Equalizer — Multi-band EQ
• Dynamics Compressor — Full-featured compressor
• Reverb — Schroeder reverb algorithm

Effects

The effects module provides modulation effects:

• Chorus — Multi-voice chorus with LFO modulation
• Flanger — Short delay with feedback and sweeping
• Phaser — All-pass filter cascade for phase shifting

Spectrum Analysis

The spectrum module provides frequency-domain analysis:

• FFT Analysis — Fast Fourier Transform with window functions
• Spectrum Analyzer — Real-time frequency analysis
• Spectrogram — Time-frequency visualization
• Waveform Display — Time-domain rendering
• Feature Extraction — Spectral features and characteristics

Audio Fingerprinting

The fingerprint module provides audio identification:

• Fingerprint Generation — Extract robust audio signatures
• Hash-based Matching — Fast database lookup
• Duplicate Detection — Find similar audio content

Loudness Normalization

The loudness module provides broadcast-standard measurement:

• EBU R128 — European Broadcasting Union standard (-23 LUFS)
• ATSC A/85 — Advanced Television Systems Committee standard (-24 LKFS)
• ITU-R BS.1770-4 — International loudness measurement algorithm
• True Peak Detection — Prevents inter-sample clipping
• Loudness Range (LRA) — Dynamic range measurement
• K-Weighting Filter — Perceptually accurate filtering

Audio Metering

The meters module provides professional metering tools:

• VU Meter — IEC 60268-10 standard with 300ms ballistics
• PPM — Peak Programme Meters (BBC, EBU, Nordic, DIN standards)
• Digital Peak Meter — Sample-accurate dBFS peak detection
• RMS Level Meter — Root mean square level measurement
• Correlation Meter — Stereo phase correlation analysis
• Goniometer — Stereo field visualization (L/R and M/S)
• LUFS Integration — Broadcast loudness metering

Spatial Audio

The spatial module provides 3D spatial audio processing (binaural, ambisonics, HRTF-based panning).

Resampling

High-quality sample rate conversion via a Pure-Rust band-limited windowed-sinc polyphase interpolator (Blackman-Harris windowed, per-phase DC-normalized, exact rational position tracking — no C/C++ dependencies):

use oximedia_audio::{Resampler, ResamplerQuality};

let mut resampler = Resampler::new(44100, 48000, 2, ResamplerQuality::High)?;
let output = resampler.resample(&input_frame)?;
let tail = resampler.flush()?; // drain stream tail at end of input

Usage

Opus Decoding

use oximedia_audio::OpusDecoder;

let mut decoder = OpusDecoder::new(48000, 2)?;
let frame = decoder.decode(&packet)?;

Opus Encoding

use oximedia_audio::OpusEncoder;

let mut encoder = OpusEncoder::new(48000, 2, 128_000)?;
let packet = encoder.encode(&frame)?;

FLAC Decoding

use oximedia_audio::FlacDecoder;

let mut decoder = FlacDecoder::new(&stream_info)?;
let frame = decoder.decode(&packet)?;

Audio Frame

use oximedia_audio::{AudioFrame, ChannelLayout};

let frame = AudioFrame::new(
    48000,                  // sample rate
    1024,                   // samples per channel
    ChannelLayout::Stereo,
);

Channel Layouts

Module Structure (115 source files, 2266 public items)

src/
├── lib.rs              # Crate root with re-exports
├── error.rs            # AudioError and AudioResult
├── frame.rs            # AudioFrame, AudioBuffer
├── traits.rs           # AudioDecoder, AudioEncoder traits
├── resample.rs         # Sample rate conversion (Pure-Rust windowed-sinc)
├── dsp/                # Digital signal processing
├── effects/            # Modulation effects
├── spectrum/           # Frequency-domain analysis
├── fingerprint/        # Audio fingerprinting
├── loudness/           # EBU R128 / ATSC A/85 / ITU-R BS.1770
├── meters/             # Professional audio metering
├── spatial/            # 3D spatial audio processing
├── opus/               # Opus codec (feature: opus)
├── vorbis/             # Vorbis codec (feature: vorbis)
├── flac/               # FLAC codec (feature: flac)
├── mp3/                # MP3 codec (feature: mp3)
└── pcm/                # PCM codec (feature: pcm)

Codec Traits

pub trait AudioDecoder {
    fn decode(&mut self, packet: &[u8]) -> AudioResult<AudioFrame>;
    fn flush(&mut self) -> AudioResult<Vec<AudioFrame>>;
}

pub trait AudioEncoder {
    fn encode(&mut self, frame: &AudioFrame) -> AudioResult<Vec<u8>>;
    fn flush(&mut self) -> AudioResult<Vec<Vec<u8>>>;
}

Policy

• No unsafe code (#![forbid(unsafe_code)])
• Apache-2.0 license

License

Apache-2.0 — Copyright 2024-2026 COOLJAPAN OU (Team Kitasan)