UAPMD is an audio plugin host that serves audio plugin instances as virtual MIDI 2.0 devices. Your can use arbitrary MIDI 2.0 client apps to:
- play MIDI 2.0 instruments with 32-bit precision; use Assignable Controllers (NRPNs) to change plugin parameters in 32-bit values (velocity in 16-bit).
- retrieve parameter list that are mapped to Assignable Controllers and Program List that are mapped to presets that are exposed via the plugin APIs. Thus you don't have to remember which controller index maps to the parameter you want, or which program number maps to the tone you need.
- save and load the plugin's state.
UAPMD targets macOS and Linux desktop. Windows builds are untested, especially support for Windows MIDI Services is not even attempted).
We support VST3, AudioUnit, LV2, and CLAP plugin formats.
UAPMD is based on its own plugin hosting foundation and released under the MIT license.
There is an application uapmd-app that performs almost all features UAPMD provides.
uapmd offers Linux packages on the release pages and GitHub Actions build artifacts, in .deb, .rpm and .tar.xz (They are based on CPack packaging tasks).
uapmd offers Homebrew package as well. You can install it as: brew install atsushieno/oss/uapmd then run /opt/homebrew/bin/uapmd-app or use those libraries the package offers.
This uapmd Git repository provides the simple normative cmake build:
$ cmake -B build # -G Ninja
$ cmake --build build
$ cmake --install build # --prefix=/usr/local
I put them on the wiki pages (note that other than the latest ones they are more like historical records).
With UAPMD, You do not have to wait for MIDI 2.0 synthesizers in the market; existing audio plugins should work as virtual MIDI 2.0 devices. We have timidity++ or fluidsynth, Microsoft GS wavetable synth, YAMAHA S-YXG etc. for MIDI 1.0. UAPMD will take a similar place for MIDI 2.0.
Currently, both Remidy and UAPMD target only desktop platforms so far, but if you use my AAP project those synth plugins already work as UMP devices (you need Android 15 or later that supports MidiUmpDeviceService).
This repository contains one primary executable uapmd-app.
There are supplemental tools for diagnosing problems we encounter.
The virtual MIDI 2.0 device service controller. Currently the command line options are hacky:
$ uapmd-app (plugin-name) (format-name) (api-name)
plugin-name is match by std::string::contains() within display name, case-sensitive.
format-name is one of VST3 AU, LV2, or CLAP.
api-name so far accepts only PIPEWIRE (on Linux) to use PipeWire, and uses default available API otherwise.
remidy-scan is a tool to query and enumerate locally installed plugins, and stores the results to (local app data)/remidy-tooling/plugin-list-cache.json (local app data depends on the platform).
ALL docs under docs are supposed to describe design investigation and thoughts.
We are moving quick and may not reflect the latest state of union, or describe our plans correctly.
There are some notable docs:
- Plugin catalog (listing) and instantiation
- State
- GUI support and main thread constraints
- Parameters
- Presets
There are two primary libraries in this repository:
remidy offers plugin API abstraction layer at lower level that primarily involves application agnostic audio and event processing. Apart from parameter API, it adopts UMP for event inputs, including parameter support via NRPN (AC, Assignable Controller) and Per-Note AC. It is an opinionated layer towards MIDI 2.0 i.e. events are parsed into timed parameter changes and other events on the plugins.
remidy-tooling offers higher level API to build audio plugin hosting tools like plugin scanning and instancing in the common manner.
What this layer introduces in practice is a set of filters; various existing specific plugin products and vendors are filtered by "safe for multithreaded access to the plugin API," "plugin scanning requires the UI thread," or "crashes remidy" kind of information.
uapmd provides reusable foundation for constructing virtual MIDI 2.0 devices upon plugin hosting layer (only remidy so far). It serves AllCtrlList MIDI-CI standard property for plugin parameters as Assignable Controllers (NRPNs), ProgramList MIDI-CI standard property for the indexed presets as Program Change, and saves and loads states in MIDI-CI property manner.
uapmd-app is a plugin host that you can list the installed plugins, instantiate plugins, process audio with a UMP keyboard, adjust parameters, select presets, launch the GUI, save, and restore the states. It also exposes those plugins as platform virtual MIDI 2.0 devices, translating UMP inputs into event inputs to those in each plugin API, as well as exposing some plugin features using MIDI-CI property exchange.
It likely works with MIDI 1.0 inputs (translated, depending on the platform) to control plugins.
Sources in this repository are released under the MIT license.
There are third-party (and first party) dependency libraries (git submodules, CMake FetchContent, or directly included):
- lv2/lv2kit (serd, sord, sratom, lilv, zix): the ISC license.
- free-audio/clap - MIT
- free-audio/clap-helpers - MIT
- steinbergmedia/vst3sdk - MIT
- Tracktion/choc: the ISC license.
- celtera/libremidi - BSD (2-clause), MIT (RtMidi)
- atsushieno/cmidi2 - MIT
- atsushieno/midicci - MIT
- [zlib-ng/zlib-ng] - Zlib license.
- mackron/miniaudio - MIT (or public domain)
- cginternals/cpplocate: the MIT license.
- jarro2783/cxxopts: the MIT license.
- cameron314/concurrentqueue - BSD (2-clause)
- cjappl/rtlog-cpp: the MIT license.
- for submodules see their LICENSE.md (modified BSD, MIT)
- cpm-cmake/CPM.cmake - MIT
- ocornut/imgui - MIT