Music2DBridge VTS

Music2DBridge is an independent third-party C# bridge for VTube Studio. It captures microphone audio, estimates musical information (note/chord/key), and injects mapped values into VTube Studio parameters through the WebSocket API.

Important

• This project is not affiliated with, endorsed by, sponsored by, or officially associated with VTube Studio or DenchiSoft.
• Music2DBridge is an external app/plugin bridge. It is not a Unity in-process plugin.
• Do not install it into VTube Studio_Data/Plugins/x86_64 as a primary setup method.

Project Structure

src/
  Music2DBridge.Core/         # Audio analysis and musical state logic
  Music2DBridge.VTubeStudio/  # VTube Studio WebSocket client/auth/inject
  Music2DBridge.App/          # Executable host app (mic capture + bridge loop)
LICENSE

Requirements

• Windows / macOS / Linux
• .NET SDK 9.0+
• VTube Studio running locally
• VTube Studio Plugin API enabled
• OpenAL runtime for microphone capture (for example libopenal1 on Linux)

In VTube Studio:

1. Open settings.
2. Enable Plugin API access.
3. Keep API port at default 8001 (or update app code if changed).

Build

From repo root:

dotnet build Music2DBridge.sln

Run (Development)

dotnet run --project src/Music2DBridge.App/Music2DBridge.App.csproj

Default launch mode is desktop UI (Avalonia).

To run in terminal/CLI mode from cmd/PowerShell:

dotnet run --project src/Music2DBridge.App/Music2DBridge.App.csproj -- --cli

At first run:

1. App connects to ws://127.0.0.1:8001
2. VTube Studio shows permission prompt
3. Allow access
4. Token is cached at:

%LocalAppData%\TamKungZ_\Music2DBridge\vts-token.txt

Publish (Single File)

Windows:

dotnet publish src/Music2DBridge.App/Music2DBridge.App.csproj -c Release -r win-x64

macOS (Intel):

dotnet publish src/Music2DBridge.App/Music2DBridge.App.csproj -c Release -r osx-x64

macOS (Apple Silicon):

dotnet publish src/Music2DBridge.App/Music2DBridge.App.csproj -c Release -r osx-arm64

Output (default):

src/Music2DBridge.App/bin/Release/net9.0/win-x64/publish/

Current Parameter Mapping

The app always injects these parameter IDs:

• ParamInstEnergy
• ParamInstPitch
• ParamInstInKey
• ParamInstChordRoot
• ParamInstChordType
• ParamInstKeyRoot
• ParamInstKeyMode

Ensure your Live2D model / VTube Studio setup uses matching parameter IDs.

Note Output Modes

Use --note-mode=<mode> or M2D_NOTE_MODE=<mode> to choose note output behavior.

• class (default): injects ParamInstNoteClass directly as note class value 0..11
• per-note: injects 12 note parameters in range 0..1 for deep rig/chord alignment

In per-note mode, the app injects these 12 parameters:

• ParamInstNoteC
• ParamInstNoteCs
• ParamInstNoteD
• ParamInstNoteDs
• ParamInstNoteE
• ParamInstNoteF
• ParamInstNoteFs
• ParamInstNoteG
• ParamInstNoteGs
• ParamInstNoteA
• ParamInstNoteAs
• ParamInstNoteB

Example:

• --note-mode=per-note

This uses fixed parameter names ParamInstNoteC ... ParamInstNoteB.

Fixed Key Filter (Optional)

You can lock detection to a key/scale. Notes outside the configured key are ignored by note/chord/key history.

• CLI argument: --fixed-key=<key>
• Environment variable: M2D_FIXED_KEY=<key>

Examples:

• --fixed-key=Cmaj
• --fixed-key=Amin
• M2D_FIXED_KEY=F# minor

Accepted key formats include major/minor suffixes (maj, major, min, minor) and sharps/flats (C#, Bb, etc.).

Audio Input Device

• GUI: choose Input from the top control bar.
• CLI argument: --input-device=<device-id>
• Environment variable: M2D_INPUT_DEVICE=<device-id>
• Default behavior: System Default (uses the computer default capture device)

On Windows, capture uses WASAPI shared mode first, so one microphone/interface can be used by multiple applications at the same time. This also works well when you are running guitar software in an ASIO host and need Music2DBridge to share the same input path.

License

This project uses a custom source-available commercial license. See LICENSE for full terms.

Commercial licensing contact:

• dev@tamkungz.me
• kittiwut.pimpromma@gmail.com