gc_adpcm

A decoder for the ADPCM bitstream used by Nintendo on the GameCube, Wii, and WiiU.

Usage

There are two ways to use this crate:

1. The Decoder API, which takes a std::io::Read and is an iterator that produces i16s (requires the std feature). This API hides intricacies of stereo interleaving.
2. The DspState API, where you manually push frames. This means you also need to take care of any interleaving yourself.

Decoder example

use gc_adpcm::{Decoder, DspState};

fn mono() {
    // There is only one audio stream
    let dsp_header: DspState = todo!(); // get the metadata from your file format
    let total_frames: u32 = todo!(); // total number of frames expected
    let reader = todo!(); // something that implements Read
    let decoder = Decoder::mono(reader, dsp_header, total_frames);
    for sample in decoder {
        let sample = sample?;
        // do something with the sample
    }
}

fn stereo() {
    // There are two separate audio streams
    let left_dsp_header: DspState = todo!(); // get the metadata from your file format
    let left_reader = todo!(); // something that implements Read
    let right_dsp_header: DspState = todo!(); // get the metadata from your file format
    let right_reader = todo!(); // something that implements Read
    let total_frames: u32 = todo!(); // total number of frames expected for one channel
    let decoder = Decoder::stereo(left_reader, left_dsp_header, right_reader, right_dsp_header, total_frames);
    // the samples are interleaved per sample, not per frame!
    for sample in decoder {
        let sample = sample?;
        // do something with the sample
    }
}

fn stereo_interleaved() {
    // There is one audio stream with two channels
    let left_dsp_header: DspState = todo!(); // get the metadata from your file format
    let right_dsp_header: DspState = todo!(); // get the metadata from your file format
    let reader = todo!(); // something that implements Read
    let total_frames: u32 = todo!(); // total number of frames expected in the stream (thus total_frames_left + total_frames_right!)
    let decoder = Decoder::stereo_interleaved(reader, left_dsp_header, right_dsp_header, total_frames);
    // the samples are interleaved per sample, not per frame!
    for sample in decoder {
        let sample = sample?;
        // do something with the sample
    }
}

DspState example

use gc_adpcm::DspState;

fn manual() {
    let mut dsp_state: DspState = todo!(); // get the metadata from your file format
    let frame: [u8; 8] = todo!(); // get a frame
    let samples = dsp_state.decode_frame(frame); // decode the frame
    // It is important that frames are processed sequentially!
    // To decode frame n, you need to have decoded frame n-1.
}

Features

std

The std enables the Decoder API. This feature is enabled by default. Disabling this feature makes this crate no_std compatible.