Cross-Platform Vst Host

General Idea

Since I found that there are not many easy-to-use command-line based VST Hosts, and some of them are no longer supported, I always wanted to create my own cmd VST Host. Unfortunately, I also found that samples provided in VST 3 SDK are way to complicated for me to use, so I decided to created my own easy-to-use repository. Thus, the main goal of this project is to learn how to work with VST 3 SDK, how to create custom VST Host and handler VST 3 Plugins. During the work on cmd-based VST Host I found out that it would be also a good idea to learn how to read audio from audio endpoint on different operation systems like Windows, Linux, MacOS and Android and process audio in real time with VST Host. So that is why this repository was created. I know that it will take a lot of work but it will also be a good way to learn about everything that I'm interested in. My idea here was also to use as many available elements as it is possible.

How to Build

1. Windows & Linux

   git submodule update --init --recursive
   pip install -r VstHost_Python/requirements.txt
   mkdir build
   cd build
   cmake ../VstHost_VisualC++ -DCMAKE_BUILD_TYPE=Release -DBUILD_GMOCK=1
   cd ..
   cmake --build build --config Release -j 8
   

2. Mac OS

   git submodule update --init --recursive
   pip install -r VstHost_Python/requirements.txt
   brew install doxygen
   mkdir build
   cd build
   cmake -G Xcode ../VstHost_VisualC++ -DCMAKE_BUILD_TYPE=Release -DCMAKE_CXX_COMPILER=gcc -DBUILD_GMOCK=1
   cd ..
   cmake --build build --config Release -j 8 --resolve-package-references on
   

3. Android

   NOTE:
   Following instruction is made for Linux enviroment. However, steps for any OS should be similar.
   1. Download Android NDK and unzip in the chosen location. (https://developer.android.com/ndk/downloads).
   
   2. Set environmental variable for Android NDK as foloow:
      
      > export ANDROID_NDK_PATH=/path/to/android/ndk/main/folder
   
   3. Build VST Host for chosen architecture:
      a. armeabi-v7a:
        > cmake "../VstHost_VisualC++" -B build_armeabi-v7a -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=RELEASE -DANDROID_PLATFORM=android-28 -D ANDROID_ABI=armeabi-v7a -DANDROID_BUILD=True
        > cd build_armeabi-v7a
        > $ANDROID_NDK_PATH/prebuilt/linux-x86_64/bin/make
      
      b. arm64-v8a:
        > cmake "../VstHost_VisualC++"  -B build_arm64-v8a -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=RELEASE -DANDROID_PLATFORM=android-28 -D ANDROID_ABI=arm64-v8a -DANDROID_BUILD=True
        > cd build_arm64-v8a
        > $ANDROID_NDK_PATH/prebuilt/linux-x86_64/bin/make
      
      c. build_x86:
        > cmake "../VstHost_VisualC++" -B build_x86 -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=RELEASE -DANDROID_PLATFORM=android-28 -D ANDROID_ABI=x86 -DANDROID_BUILD=True
        > cd build_x86
        > $ANDROID_NDK_PATH/prebuilt/linux-x86_64/bin/make
      
      d. build_x86_64:
        > cmake "../VstHost_VisualC++" -B build_x86_64 -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=RELEASE -DANDROID_PLATFORM=android-28 -D ANDROID_ABI=x86_64 -DANDROID_BUILD=True
        > cd build_x86_64
        > $ANDROID_NDK_PATH/prebuilt/linux-x86_64/bin/make
   
   4. Build Android Demo App that uses VST Host lib
      a. Copy necessery dependencess. In the example below dependeces for all architectures were copied. Also note that
         in the example VST plugin has been copied from "build_x86_64" due to the fact that Instrumentation test are 
         executed in androdi simulater on regular CPU.
   
        > mkdir VstHost_Android/AndroidPack
        > cp -rv build_armeabi-v7a/bin/Release/AndroidPack/ VstHost_Android/
        > cp -rv build_arm64-v8a/bin/Release/AndroidPack/ VstHost_Android/
        > cp -rv build_x86/bin/Release/AndroidPack/ VstHost_Android/
        > cp -rv build_x86_64/bin/Release/AndroidPack/ VstHost_Android/
        > cp -rv build_x86_64/VST3/Release VstHost_Android/app/src/main/assets
        > cp -v VstHost_VisualC++/modules/UnitTests/data/sine_440.wav VstHost_Android/app/src/main/assets/
        > cp -v VstHost_VisualC++/modules/UnitTests/data/sine_440_output_ref.wav VstHost_Android/app/src/main/assets/
      
      b. Build Android App
        > cd VstHost_Android
        > chmod +x gradlew
      
      c. Run Intrumentation Test
        > ./gradlew connectedCheck
   

Examples of usage

1. Print help: VstHostTool.exe --help
2. Dump an empty configuration needed to run the tool: VstHostTool.exe -dump_vst_host_config -vst_host_config config.json
3. Dump an empty configuration for VST plugin/plugins that will be used be. VstHostTool.exe -dump_plugins_config -vst_host_config config.json
4. Run Audio Processing with Vst Plugin. VstHostTool.exe -vst_host_config config.json

Features list

1. Platform Agnostic Features

   • Implemented:
     • CMake based project
     • Use submodules
     • Arg Parser
     • Json Reader
     • Treat Warnings as Errors
     • VST Host library in C++
     • VST Host Offline Tool in C++
     • Unit Test for library and offline tool in C++
     • CI for each configuration
     • VST Host Library with C api that allows to use it in e.g. Python
     • Basic python and android unit test for c api
     • Allow to use multiple plugins and configs for them
     • Generate Documentation
     • AudioProcessing Class that can wrap different non-vst algorithms
     • Clean up code in vst host lib
     • Cross-Platform Audio Endpoint Render-Capture
   • TODO:
     • Add more advanced python-based Vst Host Lib utilization
     • Add more UT for python and Android
     • Integrate better wave reader
     • Build solution for ARM
     • Handle different audio formats e.g. sampling rate, bit depth etc.
     • Create and pass config for AudioProcessing Class
     • Enable streaming processing (one frame in, one frame out)
     • Clean up Endpoint Manager Class

2. Android

   • TODO:
     • Add endpoint reader
     • Add platform specific offline tool

Credits (repositories used in project)

1. VST 3 SDK
2. Google Test
3. Logger
4. Arg Parser
5. Wave Reader
6. C ++ Json Handler
7. Windows Endpoint Reader
8. Implementation of audio filters in C
9. Real Timie Audio Render and Capture

VST is a trademark held by Steinberg Media Technologies, GMBH.

License

This project is licensed under the terms of the GNU GPLv3 license. Moreover, it is a derivative work of the original VST 3 SDK. However, I don't not redistribute any of the original source code.

Useful links

1. How to read data from audio endpoint (Windows, Linux, MacOS)?
2. Audio Capture on Windows
3. Treat warnings as errors on linux
4. More info about treating warnings as errors
5. How to build c++ code for Android?
6. How to use c++ .so on Android?
7. Rendering an audio stream on windows