VST Virtual Studio Technology

VST
Virtual Studio Technology
Intro to VST plug-ins & VST.NET
Kevin Reed
2012-2-21

What is VST
• an interface to
integrate
Audio Synthesizers Audio Effect Plugins
DAW (Digital Audio Workstation)

History • 1996
o SDK released by Steinberg in 1996
o released with Cubase 3.02
o included some basic effect plug-ins
• 1999
o included updates for VSTi (virtual instruments)
o Neon - the first VSTi - 16-voice, 2-oscillator virtual
analog synthesizer

Steinberg VST SDK
• "Splitting up an effect into these two parts requires some
extra efforts for an implementation of course." [1]
Vst::IComponent
Vst::IAudioProcessor
Processor
VST3 Audio Effect
Vst::EditController
Edit Controller
"But this separation
enables the host to run
each component in a
different context. It can
even run them on
different
computers." [1]

Stienberg::IAudioProcessor
• [1]
1. Setup (configuration must happen before
processing)
a. Process Setup (parameters that cannot be changed
during processing)
Stienberg::Vst::ProcessSetup
b. Dynamic Speaker Arrangements
Stienberg::Vst::IAudioProcessor::setBusArrangements
2. Process (implements actual processing)
Stienberg::Vst:IAudioProcessor::process
a. Block Size (processing done in blocks)
b. Audio Buffers
c. Parameters & Automation

VST.NET
• "VST.NET does nothing with the C++ SDK classes that
Steinberg provides. It interfaces at the lowest level with
the C function pointers and opcodes and translates those
to and from managed code (C# in this case)." [3]
• Why VST.NET [2]
• VST.NET is easier to learn than the native SDK API
• You can program VST plug-ins in any .NET language
• VST.NET provides a framework that simplifies and
clarifies the VST interfacing options
• It takes far less time to develop a managed VST.NET
plug-in than to develop a C/C++ native VST plug-in
• Good documentation
• Existing native VST knowledge applies

Implementing an Audio Processor
• using Jacobi.Vst.Core;
using Jacobi.Vst.Framework;
class AudioProcessor : IVstPluginAudioProcessor
{
public int BlockSize { get; set; }
public int InputCount {
get { return 2; }
}
public int OutputCount {
get { return 2; }
}
public double SampleRate { get; set;}
public int TailSize {
get { return 0; }
}

Audio Processor (cont.)
• public void Process(VstAudioBuffer[] inputs, VstAudioBuffer[] outputs)
{
VstAudioBuffer input = inputs[0];
VstAudioBuffer output = outputs[0]; for (int index = 0; index <
output.SampleCount; index++)
{
output[index] = input[index];
}
input = inputs[1];
output = outputs[1];
}
for (int index = 0; index < output.SampleCount; index++)
{
output[index] = input[index];
}
public bool SetPanLaw(VstPanLaw type, float gain)
{
return false;
}
}
#endregion

Changing the Interface Manager
• using Jacobi.Vst.Core;
using Jacobi.Vst.Framework;
using Jacobi.Vst.Framework.Plugin;
class MyPlugin : VstPluginWithInterfaceManagerBase
{
public MyPlugin()
: base("My Plugin",
new VstProductInfo("My Product", "My Vendor", 1000),
VstPluginCategory.Synth,
VstPluginCapabilities.NoSoundInStop,
0,
0) // enter unique plugin ID
{}
protected override IVstPluginAudioProcessor CreateAudioProcessor
(IVstPluginAudioProcessor instance)
{
if (instance == null) return new AudioProcessor(this);
}
// base class just returns 'instance'
return base.CreateAudioProcessor(instance);
}
// other methods...

References
• [1] - Stienberg VST SDK 3.5 Documentation
• http://www.steinberg.net/en/company/developer.html
• [2] - VST.NET Documentation
• http://vstnet.codeplex.com/releases/view/
58390#DownloadId=192723
• [3] - Mark's Blog Cabin
• http://obiwanjacobi.blogspot.com/2008/05/vstnet.html