synthrs

Documentation

Toy synthesiser library in Rust.

For programmatic playback, please check out the cpal integration.

Features

• Not too difficult syntax for writing your own tones (see examples)
• Basic filters (low-pass, high-pass, band-pass, band-reject, all-pass, comb, delay line, attack/decay envelope)
• Basic waveforms (sine, square, triangle, sawtooth, tangent, bastardised Karplus-Strong, and more)
• MIDI synthesis
• Basic sample synthesis (WAV)
• PCM or WAV output

Integrations

• usage with cpal
• midi-to-wav
• wasm, web synthesis

Examples (loud)

You have to right-click > download the bigger ones to your computer because GitHub does not like to stream audio

• busy signal
• bell
• mtnking-pure pure square wave
• mtnking-envelope butchered Karplus-Strong square wave with attack and decay
• gymnopedie piano sample
• rustle
• clarinet sample

Try

To run examples (list below)

cargo run --example EXAMPLE_NAME

To use as a library, add this to Cargo.toml

[dependencies.synthrs]
git = "https://github.com/gyng/synthrs"
rev = "the commit you want"

To write a custom tone to a WAV file

extern crate synthrs;

use synthrs::synthesizer::{ make_samples, quantize_samples };
use synthrs::wave::sine_wave;
use synthrs::writer::write_wav_file;

fn main() {
    // Using a predefined generator
    write_wav_file("out/sine.wav", 44_100,
        &quantize_samples::<i16>(
            &make_samples(1.0, 44_100, sine_wave(440.0))
        )
    ).expect("failed to write to file");

    // `make_samples` takes in the duration, sample rate, and a generator closure.
    // It returns an iterator which `quantize_samples` wraps around (setting the bit depth).
    write_wav_file("out/sine_closure.wav", 44_100,
        &quantize_samples::<i16>(
            &make_samples(1.0, 44_100, |t| (t * 440.0 * 2.0 * 3.14159).sin())
        )
    ).expect("failed to write to file");
}

More examples are in examples/.

Examples

Check out Cargo.toml for the full example list.

• simple generates simple tones in out/
• telecoms generates phone tones in out/
• filters generates examples of audio filtering in out/
• midi synthesises a few MIDI files in out/

This generates WAV or PCM files which can be opened in Audacity. Example MIDI files are public domain as far as I can tell.

cpal

Example usage with cpal

midi-to-wav

midi-to-wav, a simple cli to convert MIDI files to WAV

wasm

• synthrs-wasm-ts
• demo

Audacity PCM import settings

File > Import > Raw Data...

• Signed 16-bit PCM
• Little-endian
• 1 Channel (Mono)
• Sample rate: 44_100Hz (or whatever your samples generated have)

License

synthrs is licensed under the MIT License. See LICENSE for details.