audio-codec

A collection of VoIP audio codecs implemented in or wrapped for Rust. This crate provides a unified interface for encoding and decoding various audio formats commonly used in SIP, VoIP, and WebRTC applications.

Supported Codecs

Codec	Implementation	Feature
G.711 (PCMA/PCMU)	Pure Rust	Built-in
G.722	Pure Rust	Built-in
G.729	Wrapper (`g729-sys`)	Built-in
Opus	Wrapper (`opusic-sys`)	`opus` (default)
Telephone Event	RFC 4733	Built-in

Features

Unified API: Simple Encoder and Decoder traits for all codecs.
Resampler: Built-in audio resampling utility.
Lightweight: Minimal dependencies for core codecs.

Performance

Measured on Apple M2 Pro (processing 20ms audio frames):

Codec	Encode (20ms)	Decode (20ms)	Rate
PCMU/A	~50 ns	~80 ns	8kHz
G.722	~6.1 µs	~3.7 µs	16kHz
G.729	~21.8 µs	~6.2 µs	8kHz
Opus	~84.1 µs	~21.8 µs	48kHz

Note: Benchmarks run using cargo bench. Performance may vary by hardware and configuration.

Usage

Add this to your Cargo.toml:

[dependencies]
audio-codec = "0.3"

Example: Decoding PCMA

use audio_codec::{create_decoder, CodecType};

fn main() {
    let mut decoder = create_decoder(CodecType::PCMA);
    let encoded_data: Vec<u8> = vec![/* ... */];
    let pcm_samples = decoder.decode(&encoded_data);
    
    println!("Decoded {} samples", pcm_samples.len());
}

Example: Encoding G.722

use audio_codec::{create_encoder, CodecType, Encoder};

fn main() {
    let mut encoder = create_encoder(CodecType::G722);
    let pcm_samples: Vec<i16> = vec![0; 320]; // 20ms @ 16kHz mono
    let encoded_data = encoder.encode(&pcm_samples);
    
    println!("Encoded into {} bytes", encoded_data.len());
}

License

This project is licensed under the MIT License.

audio-codec 0.3.30