Module g711

G.711 Audio Codec Implementation

This module implements the G.711 codec with both μ-law (PCMU) and A-law (PCMA) variants. G.711 is the standard codec for telephony systems.

Features

• ITU-T G.711 compliant implementation
• Both A-law and μ-law encoding/decoding
• Simple single-sample functions
• Lookup table optimized for performance

Usage

Direct Function Calls

use codec_core::codecs::g711::{alaw_compress, alaw_expand, ulaw_compress, ulaw_expand};

// Single sample processing
let sample = 1024i16;
let alaw_encoded = alaw_compress(sample);
let alaw_decoded = alaw_expand(alaw_encoded);

let ulaw_encoded = ulaw_compress(sample);
let ulaw_decoded = ulaw_expand(ulaw_encoded);

Processing Multiple Samples

use codec_core::codecs::g711::{alaw_compress, alaw_expand};

let samples = vec![0i16, 100, -100, 1000, -1000];
let encoded: Vec<u8> = samples.iter().map(|&s| alaw_compress(s)).collect();
let decoded: Vec<i16> = encoded.iter().map(|&e| alaw_expand(e)).collect();

Using the G711Codec Struct

use codec_core::codecs::g711::{G711Codec, G711Variant};
use codec_core::types::{AudioCodec, CodecConfig, CodecType, SampleRate};

// Create μ-law codec
let config = CodecConfig::new(CodecType::G711Pcmu)
    .with_sample_rate(SampleRate::Rate8000)
    .with_channels(1);
let mut codec = G711Codec::new_pcmu(config)?;

// Or create A-law codec directly
let mut alaw_codec = G711Codec::new(G711Variant::ALaw);

// Encode/decode
let samples = vec![0i16; 160]; // 20ms at 8kHz
let encoded = codec.encode(&samples)?;
let decoded = codec.decode(&encoded)?;

Structs

G711Codec

G.711 codec implementation

Enums

G711Variant

G.711 codec variants

Functions

alaw_compress

A-law compression according to ITU-T G.711

alaw_expand

A-law expansion according to ITU-T G.711

init_tables

Initialize G.711 lookup tables (stub for compatibility)

ulaw_compress

μ-law compression according to ITU-T G.711

ulaw_expand

μ-law expansion according to ITU-T G.711