cridecoder

A pure Rust library for CRI Middleware codec encoding and decoding. Supports ACB/AWB audio containers, HCA (High Compression Audio) encoding/decoding, and USM video container extraction/building.

Credits

This project's CRI format implementation is based on and inspired by:

• vgmstream — a library for playing streamed audio from video games.
• PyCriCodecs — a Python library for CRI Middleware codecs.

Many thanks to the vgmstream and PyCriCodecs contributors for their reverse-engineering work on CRI Middleware formats.

Features

• ACB/AWB Extraction & Building — Parse and create CRI ACB audio containers
• ACB → WAV in one call — Extract and decode an ACB straight to WAV; the per-AWB AFS2 subkey is applied automatically for encrypted (type-56) HCA
• In-memory APIs — Every extract/decode/build operation has a variant that works on bytes/Vec<u8> without touching disk
• De-duplicated extraction — Emit each physical waveform once even when several cues share it
• HCA Encoding & Decoding — Encode PCM to HCA, decode HCA to PCM/WAV
• USM Extraction & Building — Extract or create USM video containers
• USM Metadata — Read and export USM metadata as structured JSON
• Key Testing — Test decryption keys for encrypted HCA files
• Encryption Support — Encode HCA with encryption keys
• Python bindings — pip install cridecoder exposes the full API via PyO3
• Pure Rust — No C dependencies, works on any platform Rust supports

Usage

Add to your Cargo.toml:

[dependencies]
cridecoder = "0.3"

ACB Extraction

use std::path::Path;
use cridecoder::extract_acb_from_file;

let tracks = extract_acb_from_file(
    Path::new("audio.acb"),
    Path::new("output/"),
).unwrap();

if let Some(tracks) = tracks {
    for track in &tracks {
        println!("Extracted: {}", track);
    }
}

ACB → WAV (decode in one call)

Extract an ACB and decode its HCA tracks straight to WAV. The per-AWB AFS2 subkey is applied automatically, so encrypted (type-56) ACBs only need the global keycode (pass None for unencrypted ACBs):

use std::path::Path;
use cridecoder::decode_acb_to_wav_from_file;

let paths = decode_acb_to_wav_from_file(
    Path::new("audio.acb"),
    Path::new("output/"),
    None, // Option<u64> global keycode
).unwrap();

for path in &paths {
    println!("Wrote: {path}");
}

In-memory extraction (no disk I/O)

extract_acb_to_memory returns the waveform bytes per cue. For ACBs where several cues share one physical waveform, extract_acb_unique_to_memory emits each waveform once and lists the cues that reference it:

use std::io::Cursor;
use cridecoder::extract_acb_unique_to_memory;

let acb = std::fs::read("audio.acb").unwrap();
let waveforms = extract_acb_unique_to_memory(Cursor::new(acb), None).unwrap();

for wf in &waveforms {
    let cue_names: Vec<_> = wf.cues.iter().map(|c| c.name.as_str()).collect();
    println!("{} bytes ({}) → {:?}", wf.data.len(), wf.extension, cue_names);
}

ACB Building

use std::io::Cursor;
use cridecoder::{AcbBuilder, TrackInput};

let hca_data = std::fs::read("track.hca").unwrap();
let track = TrackInput::new("my_track", 0, hca_data);

let mut builder = AcbBuilder::new();
builder.add_track(track);

let mut output = Cursor::new(Vec::new());
builder.build(&mut output, None).unwrap();

HCA to WAV

use std::fs::File;
use cridecoder::HcaDecoder;

let mut decoder = HcaDecoder::from_file("audio.hca").unwrap();
let info = decoder.info();
println!("Sample rate: {}, Channels: {}", info.sampling_rate, info.channel_count);

let mut output = File::create("output.wav").unwrap();
decoder.decode_to_wav(&mut output).unwrap();

PCM to HCA

use std::io::Cursor;
use cridecoder::{HcaEncoder, HcaEncoderConfig};

// Generate or load PCM samples (interleaved stereo f32)
let samples: Vec<f32> = vec![0.0; 44100 * 2]; // 1 second of silence

let config = HcaEncoderConfig::new(44100, 2)  // 44.1kHz stereo
    .with_bitrate(256_000);  // 256 kbps

let mut encoder = HcaEncoder::new(config).unwrap();
let mut output = Cursor::new(Vec::new());
encoder.encode(&samples, &mut output).unwrap();

USM Extraction

use std::path::Path;
use cridecoder::extract_usm_file;

let files = extract_usm_file(
    Path::new("video.usm"),
    Path::new("output/"),
    None,   // optional video decryption key
    false,  // export audio
).unwrap();

for file in &files {
    println!("Extracted: {:?}", file);
}

USM Building

use std::io::Cursor;
use cridecoder::UsmBuilder;

let video_data = std::fs::read("video.m2v").unwrap();

let builder = UsmBuilder::new("my_video".to_string())
    .video(video_data);

let mut output = Cursor::new(Vec::new());
builder.build(&mut output).unwrap();

Python

The same API is available from Python via PyO3 bindings:

pip install cridecoder

import cridecoder

# Extract + decode an ACB to WAV bytes in one call (no disk I/O).
# Encrypted (type-56) ACBs only need the global key; pass key=None otherwise.
acb = open("audio.acb", "rb").read()
for track in cridecoder.decode_acb_to_wav_bytes(acb, key=None):
    print(track["name"], track["extension"], len(track["data"]))

# De-duplicated extraction: each physical waveform once, with its cues.
for wf in cridecoder.extract_acb_unique_bytes(acb):
    print(wf["extension"], [c["name"] for c in wf["cues"]])

# Decode a standalone HCA (key/subkey for encrypted files).
wav = cridecoder.decode_hca_bytes(open("audio.hca", "rb").read())

Every disk-based function has an in-memory *_bytes counterpart that takes and returns bytes. See cridecoder.pyi for the full typed signatures.

Supported Formats

License

MIT