ZiggySynth

ZiggySynth is a SoundFont MIDI synthesizer written in pure Zig, ported from MeltySynth for C#.

Features

• Suitable for both real-time and offline synthesis.
• Support for standard MIDI files.
• No dependencies other than the standard library.
• All the functionality is in a single file.

Installation

• Zig v0.12.x is required.
• Copy ziggysynth.zig to your project.

Demo

https://www.youtube.com/watch?v=GQj3tF8OdPw

Examples

Some useful aliases:

const ziggysynth = @import("ziggysynth.zig");
const SoundFont = ziggysynth.SoundFont;
const Synthesizer = ziggysynth.Synthesizer;
const SynthesizerSettings = ziggysynth.SynthesizerSettings;
const MidiFile = ziggysynth.MidiFile;
const MidiFileSequencer = ziggysynth.MidiFileSequencer;

An example code to synthesize a simple chord:

// Load the SoundFont.
var sf2 = try fs.cwd().openFile("TimGM6mb.sf2", .{});
defer sf2.close();
var sound_font = try SoundFont.init(allocator, sf2.reader());
defer sound_font.deinit();

// Create the synthesizer.
var settings = SynthesizerSettings.init(44100);
var synthesizer = try Synthesizer.init(allocator, &sound_font, &settings);
defer synthesizer.deinit();

// Play some notes (middle C, E, G).
synthesizer.noteOn(0, 60, 100);
synthesizer.noteOn(0, 64, 100);
synthesizer.noteOn(0, 67, 100);

// The output buffer (3 seconds).
const sample_count: usize = @intCast(3 * settings.sample_rate);
var left: []f32 = try allocator.alloc(f32, sample_count);
defer allocator.free(left);
var right: []f32 = try allocator.alloc(f32, sample_count);
defer allocator.free(right);

// Render the waveform.
synthesizer.render(left, right);

Another example code to synthesize a MIDI file:

// Load the SoundFont.
var sf2 = try fs.cwd().openFile("TimGM6mb.sf2", .{});
defer sf2.close();
var sound_font = try SoundFont.init(allocator, sf2.reader());
defer sound_font.deinit();

// Create the synthesizer.
var settings = SynthesizerSettings.init(44100);
var synthesizer = try Synthesizer.init(allocator, &sound_font, &settings);
defer synthesizer.deinit();

// Load the MIDI file.
var mid = try fs.cwd().openFile("flourish.mid", .{});
defer mid.close();
var midi_file = try MidiFile.init(allocator, mid.reader());
defer midi_file.deinit();

// Create the sequencer.
var sequencer = MidiFileSequencer.init(&synthesizer);

// Play the MIDI file.
sequencer.play(&midi_file, false);

// The output buffer.
const sample_count = @as(f64, @floatFromInt(settings.sample_rate)) * midi_file.getLength();
var left: []f32 = try allocator.alloc(f32, @intFromFloat(sample_count));
defer allocator.free(left);
var right: []f32 = try allocator.alloc(f32, @intFromFloat(sample_count));
defer allocator.free(right);

// Render the waveform.
sequencer.render(left, right);

Todo

• Wave synthesis
  • [x] SoundFont reader
  • [x] Waveform generator
  • [x] Envelope generator
  • [x] Low-pass filter
  • [x] Vibrato LFO
  • [x] Modulation LFO
• MIDI message processing
  • [x] Note on/off
  • [x] Bank selection
  • [x] Modulation
  • [x] Volume control
  • [x] Pan
  • [x] Expression
  • [x] Hold pedal
  • [x] Program change
  • [x] Pitch bend
  • [x] Tuning
• Effects
  • [x] Reverb
  • [x] Chorus
• Other things
  • [x] Standard MIDI file support
  • [x] Performace optimization

License

ZiggySynth is available under the MIT license.