OdinySynth

OdinySynth is a SoundFont MIDI synthesizer written in pure Odin, ported from MeltySynth.

Demo

This is a demo video to show the synthesizer running on raylib's audio stream in real-time.

https://www.youtube.com/watch?v=edil47gQD1o

Features

• Suitable for both real-time and offline synthesis.
• Support for standard MIDI files.
• No dependencies other than the core library.

Examples

An example code to synthesize a simple chord:

using odinysynth

// Load the SoundFont.
soundfont, _ := new_soundfont("TimGM6mb.sf2")
defer destroy(&soundfont)

// Create the synthesizer.
settings := new_synthesizer_settings(44100)
synthesizer, _ := new_synthesizer(&soundfont, &settings)
defer destroy(&synthesizer)

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

// The output buffer (3 seconds).
sample_count := 3 * settings.sample_rate
left := make([]f32, sample_count)
defer delete(left)
right := make([]f32, sample_count)
defer delete(right)

// Render the waveform.
render(&synthesizer, left[:], right[:])

Another example code to synthesize a MIDI file:

using odinysynth

// Load the SoundFont.
soundfont, _ := new_soundfont("TimGM6mb.sf2")
defer destroy(&soundfont)

// Create the synthesizer.
settings := new_synthesizer_settings(44100)
synthesizer, _ := new_synthesizer(&soundfont, &settings)
defer destroy(&synthesizer)

// Load the MIDI file.
midi_file, _ := new_midi_file("flourish.mid")
defer destroy(&midi_file)

// Create the sequencer.
sequencer := new_midi_file_sequencer(&synthesizer)

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

// The output buffer.
sample_count := int(f64(settings.sample_rate) * get_length(&midi_file))
left := make([]f32, sample_count)
defer delete(left)
right := make([]f32, sample_count)
defer delete(right)

// Render the waveform.
render(&sequencer, 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
  • [ ] Reverb
  • [ ] Chorus
• Other things
  • [x] Standard MIDI file support
  • [x] Performace optimization

License

OdinySynth is available under the MIT license.