MeltySynth 2.4.1

dotnet add package MeltySynth --version 2.4.1                
NuGet\Install-Package MeltySynth -Version 2.4.1                
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="MeltySynth" Version="2.4.1" />                
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add MeltySynth --version 2.4.1                
#r "nuget: MeltySynth, 2.4.1"                
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
// Install MeltySynth as a Cake Addin
#addin nuget:?package=MeltySynth&version=2.4.1

// Install MeltySynth as a Cake Tool
#tool nuget:?package=MeltySynth&version=2.4.1                

MeltySynth

MeltySynth is a SoundFont synthesizer written in C#. The purpose of this project is to provide a MIDI music playback functionality for any .NET applications without complicated dependencies. The codebase is lightweight and can be applied to any audio drivers which support streaming audio, such as SFML.Net, Silk.NET, OpenTK, and NAudio.

The entire code is heavily inspired by the following projects:

An example code to synthesize a simple chord:

// Create the synthesizer.
var sampleRate = 44100;
var synthesizer = new Synthesizer("TimGM6mb.sf2", sampleRate);

// 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).
var left = new float[3 * sampleRate];
var right = new float[3 * sampleRate];

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

Another example code to synthesize a MIDI file:

// Create the synthesizer.
var sampleRate = 44100;
var synthesizer = new Synthesizer("TimGM6mb.sf2", sampleRate);

// Read the MIDI file.
var midiFile = new MidiFile("flourish.mid");
var sequencer = new MidiFileSequencer(synthesizer);
sequencer.Play(midiFile, false);

// The output buffer.
var left = new float[(int)(sampleRate * midiFile.Length.TotalSeconds)];
var right = new float[(int)(sampleRate * midiFile.Length.TotalSeconds)];

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

Features

  • Suitable for both real-time and offline synthesis.
  • Support for standard MIDI files with additional functionalities like dynamic tempo change.
  • No dependencies other than .NET Standard 2.1.

Installation

The NuGet package is available:

Install-Package MeltySynth

All the classes are in the MeltySynth namespace:

using MeltySynth;

If you don't like DLLs, copy all the .cs files to your project.

Playing sound

MeltySynth can only generate PCM waveforms; MeltySynth itself does not have the ability to play sound from speakers. To make the sound audible, export the generated waveform as an audio file (e.g., WAV file) or pass it to some audio driver (e.g., NAudio). If you are not very familiar with how to handle PCM audio, NAudio's tutorials should be helpful.

Note that MeltySynth does not provide thread safety. If you want to send notes and render the waveform in separate threads, you must ensure that the related methods will not be called simultaneously.

Demo

A demo song generated with Arachno SoundFont

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

A Doom port written in C# with MIDI music playback

https://www.youtube.com/watch?v=_j1izHgIT4U

A virtual keyboard made with Raylib-CsLo

https://www.youtube.com/watch?v=a8vuIq4JKhs

Use MeltySynth as a MIDI device (NAudio + loopMIDI)

https://www.youtube.com/watch?v=BiFxvzs0jUI

Use MeltySynth as a VST plugin (VST.NET)

https://www.youtube.com/watch?v=IUKIEWvw6Ik

Examples

MIDI file player for various audio drivers

Handling SoundFont

To enumerate samples in the SoundFont:

var soundFont = new SoundFont("TimGM6mb.sf2");

foreach (var sample in soundFont.SampleHeaders)
{
    Console.WriteLine(sample.Name);
}

To enumerate instruments in the SoundFont:

var soundFont = new SoundFont("TimGM6mb.sf2");

foreach (var instrument in soundFont.Instruments)
{
    Console.WriteLine(instrument.Name);
}

To enumerate presets in the SoundFont:

var soundFont = new SoundFont("TimGM6mb.sf2");

foreach (var preset in soundFont.Presets)
{
    var bankNumber = preset.BankNumber.ToString("000");
    var patchNumber = preset.PatchNumber.ToString("000");

    Console.WriteLine($"{bankNumber}:{patchNumber} {preset.Name}");
}

Handling synthesizer

To change the instrument to play, send a program change command (0xC0) to the synthesizer:

// Create the synthesizer.
var sampleRate = 44100;
var synthesizer = new Synthesizer("TimGM6mb.sf2", sampleRate);

// Change the instrument to electric guitar (#30).
synthesizer.ProcessMidiMessage(0, 0xC0, 30, 0);

// 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).
var left = new float[3 * sampleRate];
var right = new float[3 * sampleRate];

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

To play a melody, render the sound as a sequence of short blocks:

// Create the synthesizer.
var sampleRate = 44100;
var synthesizer = new Synthesizer("TimGM6mb.sf2", sampleRate);

// The length of a block is 0.1 sec.
var blockSize = sampleRate / 10;

// The entire output is 3 sec.
var blockCount = 30;

// Define the melody.
// A single row indicates the start timing, end timing, and pitch.
var data = new int[][]
{
    new int[] {  5, 10, 60 },
    new int[] { 10, 15, 64 },
    new int[] { 15, 25, 67 }
};

// The output buffer.
var left = new float[blockSize * blockCount];
var right = new float[blockSize * blockCount];

for (var t = 0; t < blockCount; t++)
{
    // Process the melody.
    foreach (var row in data)
    {
        if (t == row[0]) synthesizer.NoteOn(0, row[2], 100);
        if (t == row[1]) synthesizer.NoteOff(0, row[2]);
    }

    // Render the block.
    var blockLeft = left.AsSpan(blockSize * t, blockSize);
    var blockRight = right.AsSpan(blockSize * t, blockSize);
    synthesizer.Render(blockLeft, blockRight);
}

Handling MIDI file sequencer

To change the playback speed:

// Create the synthesizer.
var sampleRate = 44100;
var synthesizer = new Synthesizer("TimGM6mb.sf2", sampleRate);

// Read the MIDI file.
var midiFile = new MidiFile(@"C:\Windows\Media\flourish.mid");
var sequencer = new MidiFileSequencer(synthesizer);

// Play the MIDI file.
sequencer.Play(midiFile, false);

// Change the playback speed.
sequencer.Speed = 1.5F;

// The output buffer.
var left = new float[(int)(sampleRate * midiFile.Length.TotalSeconds / sequencer.Speed)];
var right = new float[(int)(sampleRate * midiFile.Length.TotalSeconds / sequencer.Speed)];

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

To mute a certain track:

// Create the synthesizer.
var sampleRate = 44100;
var synthesizer = new Synthesizer("TimGM6mb.sf2", sampleRate);

// Read the MIDI file.
var midiFile = new MidiFile(@"C:\Windows\Media\flourish.mid");
var sequencer = new MidiFileSequencer(synthesizer);

// Discard MIDI messages if its channel is the percussion channel.
sequencer.OnSendMessage = (synthesizer, channel, command, data1, data2) =>
{
    if (channel == 9)
    {
        return;
    }

    synthesizer.ProcessMidiMessage(channel, command, data1, data2);
};

// Play the MIDI file.
sequencer.Play(midiFile, false);

// The output buffer.
var left = new float[(int)(sampleRate * midiFile.Length.TotalSeconds)];
var right = new float[(int)(sampleRate * midiFile.Length.TotalSeconds)];

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

To change the instruments used in the MIDI file:

// Create the synthesizer.
var sampleRate = 44100;
var synthesizer = new Synthesizer("TimGM6mb.sf2", sampleRate);

// Read the MIDI file.
var midiFile = new MidiFile(@"C:\Windows\Media\flourish.mid");
var sequencer = new MidiFileSequencer(synthesizer);

// Turn all the instruments into electric guitars.
sequencer.OnSendMessage = (synthesizer, channel, command, data1, data2) =>
{
    if (command == 0xC0)
    {
        data1 = 30;
    }

    synthesizer.ProcessMidiMessage(channel, command, data1, data2);
};

// Play the MIDI file.
sequencer.Play(midiFile, false);

// The output buffer.
var left = new float[(int)(sampleRate * midiFile.Length.TotalSeconds)];
var right = new float[(int)(sampleRate * midiFile.Length.TotalSeconds)];

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

Todo

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

License

MeltySynth is available under the MIT license.

References

Product Compatible and additional computed target framework versions.
.NET net5.0 was computed.  net5.0-windows was computed.  net6.0 was computed.  net6.0-android was computed.  net6.0-ios was computed.  net6.0-maccatalyst was computed.  net6.0-macos was computed.  net6.0-tvos was computed.  net6.0-windows was computed.  net7.0 was computed.  net7.0-android was computed.  net7.0-ios was computed.  net7.0-maccatalyst was computed.  net7.0-macos was computed.  net7.0-tvos was computed.  net7.0-windows was computed.  net8.0 was computed.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed. 
.NET Core netcoreapp3.0 was computed.  netcoreapp3.1 was computed. 
.NET Standard netstandard2.1 is compatible. 
MonoAndroid monoandroid was computed. 
MonoMac monomac was computed. 
MonoTouch monotouch was computed. 
Tizen tizen60 was computed. 
Xamarin.iOS xamarinios was computed. 
Xamarin.Mac xamarinmac was computed. 
Xamarin.TVOS xamarintvos was computed. 
Xamarin.WatchOS xamarinwatchos was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.
  • .NETStandard 2.1

    • No dependencies.

NuGet packages (1)

Showing the top 1 NuGet packages that depend on MeltySynth:

Package Downloads
Spice86.Core

Reverse engineer and rewrite real mode dos programs

GitHub repositories (3)

Showing the top 3 popular GitHub repositories that depend on MeltySynth:

Repository Stars
sinshu/managed-doom
A Doom port written in C#
OpenRakis/Spice86
Reverse engineer and rewrite real mode DOS programs!
sinshu/meltysynth
A SoundFont MIDI synthesizer for .NET
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