Comment by mpduda

Still working on my software project for live music production [1]. At the moment, it only creates, forwards, and records MIDI note events, so it can't produce audio on its own. It has to be connected to external or virtual MIDI devices that can create sound. Turns out this is too much of a hassle and kind of a deal-breaker for most people (and to be fair, it is a hassle), so now I'm working on adding VST hosting support directly inside the app. If you're not familiar, VST (Steinberg Virtual Studio Technology) is pretty much the industry standard plugin system that most DAWs support. Different VSTs can create and filter audio data, and in a hosted context audio data can be sent between VST instances before going out to the speakers.

It's been tricky but interesting. VST plugins are basically packaged as DLL files of Windows COM(-ish) objects. Despite primarily being a Windows dev myself, I never worked directly with COM libraries or objects before. My app is written in C#, and .NET does have built-in "COM Interop" support, so it is possible. A few years ago, .NET added a new COM Interop Source Generator system [2, 3], and I'm trying to get it working with that. So far I've been making some progress, but it's still a lot of tedious work to setup.

(There are libraries/packages out there that implement VST in .NET already, but they mostly focus on plugin creation while I only need hosting. They're a lot heavier and more capable than I need. They also didn't use the newer Source Generator approach, so I figured I'd give it a shot myself.)

1. https://www.pulselyre.com/

2. https://learn.microsoft.com/en-us/dotnet/standard/native-int...

3. https://www.youtube.com/watch?v=DZd1SGd7dSU