NIH-plug

This is a hard fork of https://github.com/robbert-vdh/nih-plug, since the original author is no longer maintaining it.

This fork does NOT contain the original collection of plugins. If you are looking for those, go to the original repository linked above. Please do NOT post any issues about the original plugins here, this is for the development framework only!

This repository has moved to Codeberg https://codeberg.org/BillyDM/nih-plug. Please only post issues and pull requests there. A read-only mirror is available at https://github.com/BillyDM/nih-plug for users who prefer that.

NIH-plug is an API-agnostic audio plugin framework written in Rust.

The idea is to have a stateful yet simple plugin API that gets rid of as much unnecessary ceremony wherever possible, while also keeping the amount of magic to a minimum and making it easy to experiment with different approaches to things. See the current features section for more information on the project's current status.

Table of contents

• Baseview adapters
• Framework
  • Current features
  • Building
  • Plugin formats
  • Example plugins
• Licensing

Baseview adapters

This repository contains baseview adapters for popular Rust GUI frameworks. These can be used on their own without the rest of the NIH-plug framework.

• egui-baseview - adapter for egui
• iced_baseview - adapter for Iced

Framework

For a list of available crate flags, see crates/nih_plug/Cargo.toml.

Current features

• Supports both VST3 and CLAP by simply adding the corresponding nih_export_<api>!(Foo) macro to your plugin's library.
• Standalone binaries can be made by calling nih_export_standalone(Foo) from your main() function. Standalones come with a CLI for configuration and full JACK audio, MIDI, and transport support.
• Rich declarative parameter system without any boilerplate.
  • Define parameters for your plugin by adding FloatParam, IntParam, BoolParam, and EnumParam<T> fields to your parameter struct, assign stable IDs to them with the #[id = "foobar"], and a #[derive(Params)] does all of the boring work for you.
  • Parameters can have complex value distributions and the parameter objects come with built-in smoothers and callbacks.
  • Use simple enums deriving the Enum trait with the EnumParam<T> parameter type for parameters that allow the user to choose between multiple discrete options. That way you can use regular Rust pattern matching when working with these values without having to do any conversions yourself.
  • Store additional non-parameter state for your plugin by adding any field that can be serialized with Serde to your plugin's Params object and annotating them with #[persist = "key"].
  • Optional support for state migrations, for handling breaking changes in plugin parameters.
  • Group your parameters into logical groups by nesting Params objects using the #[nested(group = "...")]attribute.
  • The #[nested] attribute also enables you to use multiple copies of the same parameter, either as regular object fields or through arrays.
  • When needed, you can also provide your own implementation for the Params trait to enable compile time generated parameters and other bespoke functionality.
• Stateful. Behaves mostly like JUCE, just without all of the boilerplate.
• Comes with a simple yet powerful way to asynchronously run background tasks from a plugin that's both type-safe and realtime-safe.
• Does not make any assumptions on how you want to process audio, but does come with utilities and adapters to help with common access patterns.
  • Efficiently iterate over an audio buffer either per-sample per-channel, per-block per-channel, or even per-block per-sample-per-channel with the option to manually index the buffer or get access to a channel slice at any time.
  • Easily leverage per-channel SIMD using the SIMD adapters on the buffer and block iterators.
  • Comes with bring-your-own-FFT adapters for common (inverse) short-time Fourier Transform operations. More to come.
• Optional sample accurate automation support for VST3 and CLAP that can be enabled by setting the Plugin::SAMPLE_ACCURATE_AUTOMATION constant to true.
• Optional support for compressing the human readable JSON state files using Zstandard.
• Comes with adapters for popular Rust GUI frameworks as well as some basic widgets for them that integrate with NIH-plug's parameter system:
  • nih_plug_egui - Adapter for egui. See the egui-baseview crate for prerequisites.
  • nih_plug_iced - Adapter for Iced. See the iced_baseview crate for prerequisites.
• Full support for receiving and outputting both modern polyphonic note expression events as well as MIDI CCs, channel pressure, and pitch bend for CLAP and VST3.
  • MIDI SysEx is also supported. Plugins can define their own structs or sum types to wrap around those messages so they don't need to interact with raw byte buffers in the process function.
• Support for flexible dynamic buffer configurations, including variable numbers of input and output ports.
• First-class support several more exotic CLAP features:
  • Both monophonic and polyphonic parameter modulation are supported.
  • Plugins can declaratively define pages of remote controls that DAWs can bind to hardware controllers.
• A plugin bundler accessible through the cargo xtask bundle <package> <build_arguments> command that automatically detects which plugin targets your plugin exposes and creates the correct plugin bundles for your target operating system and architecture, with cross-compilation support. The cargo subcommand can easily be added to your own project as an alias or globally as a regular cargo subcommand.
• Tested on Linux and Windows, with limited testing on macOS. Windows support has mostly been tested through Wine with yabridge.
• See the Plugin trait's documentation for an incomplete list of the functionality that has currently not yet been implemented.

Building

NIH-plug works with the latest stable Rust compiler.

After installing Rust, you can compile any of the plugins in the plugins directory in the following way, replacing gain with the name of the plugin:

cargo xtask bundle gain --release

Plugin formats

NIH-plug can currently export VST3 and CLAP plugins. Exporting a specific plugin format for a plugin is as simple as calling the nih_export_<format>!(Foo); macro. The cargo xtask bundle command will detect which plugin formats your plugin supports and create the appropriate bundles accordingly, even when cross compiling.

Example plugins

The best way to get an idea for what the API looks like is to look at the examples.

• gain is a simple smoothed gain plugin that shows off a couple other parts of the API, like support for storing arbitrary serializable state.
• gain_<gui> are the same plugins as gain, but with a GUI to control the parameter and a digital peak meter.
  • gain_egui - See the egui-baseview crate for prerequisites.
  • gain_iced - See the iced_baseview crate for prerequisites.
• Examples for adding your own custom GUI framework on top of raw rendering APIs:
  • byo_gui_gl - for rendering with OpenGL
  • byo_gui_wgpu - for rendering with wgpu
  • byo_gui_softbuffer - for rendering with softbuffer (software rendering)
• midi_inverter takes note/MIDI events and flips around the note, channel, expression, pressure, and CC values. This example demonstrates how to receive and output those events.
• poly_mod_synth is a simple polyphonic synthesizer with support for polyphonic modulation in supported CLAP hosts. This demonstrates how polyphonic modulation can be used in NIH-plug.
• sine is a simple test tone generator plugin with frequency smoothing that can also make use of MIDI input instead of generating a static signal based on the plugin's parameters.
• stft shows off some of NIH-plug's other optional higher level helper features, such as an adapter to process audio with a short-term Fourier transform using the overlap-add method, all using the compositional Buffer interfaces.
• sysex is a simple example of how to send and receive SysEx messages by defining custom message types.

Contributing

Please refer to the Rust Audio community's policy an AI usage: https://rust.audio/community/ai/

Nih-plug uses optional nightly features. To make rust analyzer happy, you can enable the nightly compiler for your local repository with:

rustup override add nightly

Licensing

Check each crate's Cargo.toml file for more information.

The framework, all of the crates in crates/, and the example plugins in examples/ are all licensed under the ISC license.

All of the crates in baseview-adapters/ are licensed under "MIT or Apache-2.0".

However, the VST3 bindings used by nih_export_vst3!() are licensed under the GPLv3 license. This means that unless you replace these bindings with your own bindings made from scratch, any VST3 plugins built with NIH-plug need to be able to comply with the terms of the GPLv3 license.