Native Instruments NCW Audio File Format

Description

NCW (Native Instruments Compressed Wave) is a lossless compression algorithm developed by Native Instruments which is essentially DPCM and bit truncation.

This library is a zero-dependency Rust-based library to decode NCW files. It serves as part of a wider reverse engineering effort of proprietary audio formats, and this particular library is used in ni-file.

This repository also includes an ncw to wav conversion cli tool, ncw-decode.

Requirements

• Rust 1.50 or higher

Usage

let input = File::open(&args[1])?;
let mut output = File::create(&args[2])?;
let mut ncw = NcwReader::read(&input)?;

let spec = WavSpec {
		channels: ncw.header.channels,
		sample_rate: ncw.header.sample_rate,
		bits_per_sample: ncw.header.bits_per_sample,
		sample_format: hound::SampleFormat::Int,
};

for sample in ncw.decode_samples()? {
	// save or convert each sample into a file or stream
	dbg!(sample);
}

Utility (ncw-convert)

To install the cli utility, you can use cargo:

cargo install ncw-convert

Usage

Run the program with the following command-line arguments:

ncw-convert <INPUT> <OUTPUT>

• <INPUT>: Path to the input NCW file.
• <OUTPUT>: Path where the output WAV file will be saved.

Contribution

To contribute, create a pull request with your proposed changes.