OwnVst3

A lightweight C++ wrapper for loading and working with VST3 plugins.

Overview

OwnVst3Host is a C++ library that provides a simplified interface for hosting VST3 plugins in your applications. It handles the complex details of the VST3 SDK and provides an easy-to-use API for loading plugins, manipulating parameters, processing audio, and handling MIDI events.

Features

• Load VST3 plugins from file paths
• Get plugin information (name, vendor, etc.)
• Create and manage plugin editor UI
• List, get, and set plugin parameters
• Process audio through plugins
• Send MIDI events to instrument plugins
• Detect plugin types (instrument vs effect)
• Cross-platform support (Windows, macOS, Linux)

Requirements

• C++17 or higher
• VST3 SDK (Steinberg)
• Windows, macOS, or Linux operating system

Git clone

git clone --recurse-submodules https://github.com/ModernMube/OwnVST3.git

Installation

1. Include the OwnVst3Host header and source files in your project
2. Make sure the VST3 SDK is properly set up and linked
3. When building as a DLL, define:
   • OWN_VST3_HOST_EXPORTS for the C++ API
   • OWN_VST3_WRAPPER_EXPORTS for the C wrapper API

Build Windows

mkdir build
cd build
cmake ..
cmake --build .

Build Mac and Linux

mkdir build
cd build
cmake ..
make

Basic Usage

#include "ownvst3.h"
#include <iostream>
#include <vector>

int main() {
    // Create plugin instance
    OwnVst3Host::Vst3Plugin plugin;
    
    // Load a VST3 plugin
    if (plugin.loadPlugin("C:/Path/To/YourPlugin.vst3")) {
        // Initialize with sample rate and block size
        plugin.initialize(44100.0, 512);
        
        // Print plugin information
        std::cout << "Plugin loaded: " << plugin.getName() << std::endl;
        std::cout << plugin.getPluginInfo() << std::endl;
        
        // Get parameters
        auto params = plugin.getParameters();
        std::cout << "Parameters:" << std::endl;
        for (const auto& param : params) {
            std::cout << "  " << param.name << " (ID: " << param.id << ")" << std::endl;
        }
        
        // Create audio buffer for processing
        float* inputBuffer[2] = { /* your input data */ };
        float* outputBuffer[2] = { /* buffer for output data */ };
        
        OwnVst3Host::AudioBuffer buffer;
        buffer.inputs = inputBuffer;
        buffer.outputs = outputBuffer;
        buffer.numChannels = 2;
        buffer.numSamples = 512;
        
        // Process audio
        plugin.processAudio(buffer);
        
        // Or send MIDI events if it's an instrument
        if (plugin.isInstrument()) {
            std::vector<OwnVst3Host::MidiEvent> midiEvents;
            // Add note-on event
            OwnVst3Host::MidiEvent noteOn;
            noteOn.status = 0x90; // Note on, channel 0
            noteOn.data1 = 60;    // C4
            noteOn.data2 = 100;   // Velocity
            noteOn.sampleOffset = 0;
            midiEvents.push_back(noteOn);
            
            plugin.processMidi(midiEvents);
        }
    }
    
    return 0;
}

API Documentation

Vst3Plugin Class

The main class for interacting with VST3 plugins.

Constructor/Destructor

• Vst3Plugin() - Creates a new VST3 plugin instance
• ~Vst3Plugin() - Cleans up and releases resources

Plugin Loading and Initialization

• bool loadPlugin(const std::string& pluginPath) - Loads a VST3 plugin from the specified path
• bool initialize(double sampleRate, int maxBlockSize) - Initializes the plugin with sample rate and block size

Editor Management

• bool createEditor(void* windowHandle) - Creates and attaches the plugin's editor to a window
• void closeEditor() - Closes the plugin editor
• void resizeEditor(int width, int height) - Resizes the plugin editor window
• bool getEditorSize(int& width, int& height) - Gets the editor's preferred size
• void processIdle() - Processes idle events (should be called periodically from UI thread)
• bool isEditorOpen() - Checks if the editor window is currently open

Parameter Management

• std::vector<Vst3Parameter> getParameters() - Gets all available parameters
• int getParameterCount() - Gets total parameter count
• bool getParameterInfo(int index, Vst3Parameter& outParam) - Gets parameter by index
• bool setParameter(int paramId, double value) - Sets a parameter value
• double getParameter(int paramId) - Gets a parameter value

Audio and MIDI Processing

• bool processAudio(AudioBuffer& buffer) - Processes audio through the plugin
• bool processMidi(const std::vector<MidiEvent>& events) - Sends MIDI events to the plugin
• int getActualInputChannels() - Gets the actual input channel count accepted by the plugin
• int getActualOutputChannels() - Gets the actual output channel count accepted by the plugin

Transport State

• void setTempo(double bpm) - Sets the playback tempo (BPM)
• void setTransportState(bool playing) - Sets the transport playing state
• void resetTransportPosition() - Resets the transport sample position counter

Plugin Type

• bool isInstrument() - Checks if the plugin is an instrument
• bool isEffect() - Checks if the plugin is an effect
• bool isMidiOnly() - Checks if the plugin accepts MIDI but has no audio output

Plugin Information

• std::string getName() - Gets the plugin name
• std::string getVendor() - Gets the plugin vendor
• std::string getVersion() - Gets the plugin version
• std::string getPluginInfo() - Gets formatted plugin information

C Wrapper API

A C-compatible wrapper is available for use with languages that can interface with C but not C++. Include ownvst3_wrapper.h for access.

Functions

• VST3PluginHandle VST3Plugin_Create() - Creates a new plugin instance
• void VST3Plugin_Destroy(VST3PluginHandle handle) - Destroys a plugin instance
• bool VST3Plugin_LoadPlugin(VST3PluginHandle handle, const char* pluginPath) - Loads a plugin
• bool VST3Plugin_Initialize(VST3PluginHandle handle, double sampleRate, int maxBlockSize) - Initializes the plugin
• bool VST3Plugin_CreateEditor(VST3PluginHandle handle, void* windowHandle) - Creates editor
• void VST3Plugin_CloseEditor(VST3PluginHandle handle) - Closes editor
• void VST3Plugin_ResizeEditor(VST3PluginHandle handle, int width, int height) - Resizes editor
• bool VST3Plugin_GetEditorSize(VST3PluginHandle handle, int* width, int* height) - Gets editor size
• void VST3Plugin_ProcessIdle(VST3PluginHandle handle) - Processes idle events
• bool VST3Plugin_IsEditorOpen(VST3PluginHandle handle) - Checks if editor is currently open
• int VST3Plugin_GetParameterCount(VST3PluginHandle handle) - Gets parameter count
• bool VST3Plugin_GetParameterAt(VST3PluginHandle handle, int index, VST3ParameterC* parameter) - Gets parameter by index
• bool VST3Plugin_SetParameter(VST3PluginHandle handle, int paramId, double value) - Sets parameter
• double VST3Plugin_GetParameter(VST3PluginHandle handle, int paramId) - Gets parameter value
• bool VST3Plugin_ProcessAudio(VST3PluginHandle handle, AudioBufferC* buffer) - Processes audio
• bool VST3Plugin_ProcessMidi(VST3PluginHandle handle, const MidiEventC* events, int eventCount) - Processes MIDI
• int VST3Plugin_GetActualInputChannels(VST3PluginHandle handle) - Gets actual input channels
• int VST3Plugin_GetActualOutputChannels(VST3PluginHandle handle) - Gets actual output channels
• void VST3Plugin_SetTempo(VST3PluginHandle handle, double bpm) - Sets playback tempo
• void VST3Plugin_SetTransportState(VST3PluginHandle handle, bool isPlaying) - Sets transport state
• void VST3Plugin_ResetTransportPosition(VST3PluginHandle handle) - Resets transport position
• bool VST3Plugin_IsInstrument(VST3PluginHandle handle) - Checks if instrument
• bool VST3Plugin_IsEffect(VST3PluginHandle handle) - Checks if effect
• bool VST3Plugin_IsMidiOnly(VST3PluginHandle handle) - Checks if plugin is MIDI only
• const char* VST3Plugin_GetName(VST3PluginHandle handle) - Gets plugin name
• const char* VST3Plugin_GetVendor(VST3PluginHandle handle) - Gets plugin vendor
• const char* VST3Plugin_GetVersion(VST3PluginHandle handle) - Gets plugin version
• const char* VST3Plugin_GetPluginInfo(VST3PluginHandle handle) - Gets plugin info
• void VST3Plugin_ClearStringCache() - Clears the internal string cache

License

This project is available under the MIT License.

Acknowledgements

Based on the VST3 SDK by Steinberg Media Technologies GmbH.

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