Munt.NET

A .NET wrapper for the Munt mt32emu library, providing Roland CM-32L/MT-32 emulation.

The NuGet package includes pre-built native mt32emu libraries for Windows (x64), Linux (x64), and macOS (ARM64) — no need to build mt32emu yourself.

Installation

dotnet add package Munt.NET

Usage

Render MIDI messages to PCM

using Munt.NET;

using var synth = new Mt32EmuSynth();
synth.LoadRoms("CM32L_CONTROL.ROM", "CM32L_PCM.ROM");
synth.SetSampleRate(44100);
synth.Open();

// Send MIDI messages (packed 32-bit: status | data1<<8 | data2<<16)
synth.PlayMsg(0x6440C0); // Program Change: channel 0, program 0x40
synth.PlayMsg(0x647F90); // Note On: channel 0, note 0x40, velocity 0x7F

// Render to 16-bit stereo PCM
short[] buffer = new short[4096];
synth.Render(buffer, 2048); // 2048 stereo frames

Render an XMI file to PCM

using Munt.NET;

using var synth = new Mt32EmuSynth();
synth.LoadRoms("CM32L_CONTROL.ROM", "CM32L_PCM.ROM");
synth.SetSampleRate(44100);
synth.Open();

short[] pcm = XmiSequencer.RenderXmiToPcm(synth, "music.xmi", sampleRate: 44100);
// pcm contains interleaved 16-bit stereo samples

ROM Files

CM-32L or MT-32 ROM files are required but cannot be distributed with this package. You must source them separately. Both standard names and MAME-style names are supported:

• CM32L_CONTROL.ROM / cm32l_ctrl_1_02.rom / cm32l_ctrl_1_00.rom
• CM32L_PCM.ROM / cm32l_pcm.rom

Platform Support

Platform	Runtime ID	Included in NuGet
Windows x64	win-x64	Yes
Linux x64	linux-x64	Yes
macOS ARM64	osx-arm64	Yes

Building from Source

Only needed if you're contributing or need a platform not listed above.

# Clone
git clone https://github.com/abedegno/Munt.NET.git
cd Munt.NET

# Build the mt32emu native library (requires cmake)
git clone --depth 1 https://github.com/munt/munt.git munt-src
cd munt-src/mt32emu
cmake -B build -DCMAKE_BUILD_TYPE=Release -Dlibmt32emu_SHARED=ON
cmake --build build --config Release

# Copy native lib to runtimes (macOS example)
mkdir -p ../../src/Munt.NET/runtimes/osx-arm64/native
cp build/libmt32emu.dylib ../../src/Munt.NET/runtimes/osx-arm64/native/
cd ../..

# On macOS you can also install via Homebrew
# brew install mt32emu
# cp /opt/homebrew/lib/libmt32emu.dylib src/Munt.NET/runtimes/osx-arm64/native/

# Build and test
dotnet build Munt.NET.sln
dotnet test Munt.NET.sln

License

This wrapper is licensed under the MIT License.

The mt32emu native library is licensed under LGPL-2.1-or-later and is distributed as a shared library in compliance with the LGPL.

Credits

• Munt — the mt32emu MT-32/CM-32L emulation engine