Add NullOutput to discard audio

Author: smeyfroi

src/SoundObjects/NullOutput.h

@@ -0,0 +1,22 @@
+//
+//  NullObject.hpp
+//
+//  Created by smeyfroi on 2025-04-20.
+//
+#pragma once
+
+#include "ofxSoundObject.h"
+
+// An output sink that discards incoming audio when a SoundObject stream
+// is being used live for audio analysis and output is not needed.
+//
+//   ...
+//   soundStream.setup(settings);
+//   soundStream.setInput(deviceInput);
+//   soundStream.setOutput(nullOutput);
+//
+//   deviceInput.connectTo(*this).connectTo(nullOutput);
+//
+class NullOutput: public ofxSoundOutput {
+  void process(ofSoundBuffer &input, ofSoundBuffer &output) override {};
+};