Audio

Waveforms and features through the same matrix runtime.

OA Audio is a compact offline, batched, capture, playback, and media layer. It uses explicit Float32 channel-major buffers and composes with the Core, Vision, and ML modules.

Rust · PythonWAV · FLAC · MP3 decodeFloat32-first

A luminous grand piano beneath audio light trails — Audio

Input and output

File decode

WAV, FLAC, and MP3 decode to semantic oa::Audio values backed by planar Float32 matrices with attached rate and channel layout.

Capture

A bounded real-time device ring publishes timestamped Float32 chunks without blocking the audio callback.

Playback

oa::audio::AudioPlayer supports incremental decode, play, pause, seek, loop, and monotonic position tracking.

Encoding

Lossless WAV-F32 output is public; stateful encoders expose their own packet contracts. FLAC and Opus encoding remain roadmap work.

Verified operations

Group	Operations
I/O	Load file or memory; save WAV-F32
Signal	Gain, mix, fade, clip, pre-emphasis, mono, normalization, resampling
Features	STFT magnitude, mel spectrogram, MFCC, amplitude to dB
Interop	Zero-copy raw-audio matrix view

Audio processing example

STFT, mel, and MFCC outputs are ordinary oa::Matrix values. The feature path can therefore feed a model without a second tensor type or an adapter framework.

1use anyhow::Context;
2use oa::{Engine, Filesystem, Path, audio};
3
4fn main() -> anyhow::Result<()> {
5	let engine = Engine::new().context("create OA engine")?;
6
7	let audio_path = Path::asset_rel("audio/oaNarration.wav");
8
9	let output = Path::var_rel("example/audio/oaNarrationRoom.wav");
10	Filesystem::create_directories(&output.parent().unwrap())?;
11
12	let source = audio::decode_file(&engine, &audio_path)
13		.with_context(|| format!("decode {}", audio_path.display()))?;
14	let mono = audio::to_mono(&source)?;
15	let normalized = audio::normalize(
16		&mono,
17		audio::NormalizeAudioConfig {
18			target_db: -3.0,
19			..Default::default()
20		},
21	)?;
22	let faded = audio::fade(&normalized, 2400, 2400)?;
23	let reverberated = audio::reverb(&faded, 1.5, 0.4)?;
24	audio::save_wav_f32(&output, &reverberated)?;
25
26	assert!(reverberated.channels() == 1);
27	assert!(output.is_file());
28
29	println!(
30		"Saved reverberated audio (1.5 s tail): {}",
31		output.display()
32	);
33	Ok(())
34}
35

Media integration

Video sessions can open the first audio track from the same URI and preserve video-only operation when no compatible track exists. Capture and recording share timestamps with Vision; entropy codecs remain explicit CPU codec boundaries around Vulkan DSP.