Clear audio output in Device before Ports process buffers.

src/audio.cpp

@@ -31,6 +31,9 @@ void Device::unsubscribe(Port* port) {
 }
 
 void Device::processBuffer(const float* input, int inputStride, float* output, int outputStride, int frames) {
+	// Zero output since Ports might not write to all elements, or no Ports exist
+	std::fill_n(output, frames * outputStride, 0.f);
+
 	std::lock_guard<std::mutex> lock(processMutex);
 	for (Port* port : subscribed) {
 		// Setting the thread context should probably be the responsibility of Port, but because processInput() etc are overridden, this is the only good place for it.
@@ -45,11 +48,6 @@ void Device::processBuffer(const float* input, int inputStride, float* output, i
 		contextSet(port->context);
 		port->processOutput(output + port->outputOffset, outputStride, frames);
 	}
-
-	if (subscribed.empty()) {
-		// Clear output if no Port writes values to it.
-		std::fill_n(output, frames * outputStride, 0.f);
-	}
 }
 
 void Device::onStartStream() {