Prevent ArrayIndexOutOfBoundsException when none of the devices have …

…any inputs

src/processing/sound/Engine.java

@@ -138,6 +138,7 @@ private void createSynth(AudioDeviceManager deviceManager) {
 		if (this.synth != null) {
 			this.stopSynth(true);
 		}
+		// this might be -1 if there is no device with inputs. handled below.
 		this.inputDevice = deviceManager.getDefaultInputDeviceID();
 		this.outputDevice = deviceManager.getDefaultOutputDeviceID();
 		this.synth = JSyn.createSynthesizer(deviceManager);
@@ -191,6 +192,9 @@ private void startSynth() {
 		}
 		this.setVolume(1.0f);
 
+		// prevent IndexOutOfBoundsException on input-less devices
+		int inputChannels = this.inputDevice >= 0 ?
+			this.synth.getAudioDeviceManager().getMaxInputChannels(this.inputDevice) : 0;
 		this.synth.start(this.sampleRate,
 				this.inputDevice, this.synth.getAudioDeviceManager().getMaxInputChannels(this.inputDevice),
 				this.outputDevice, this.synth.getAudioDeviceManager().getMaxOutputChannels(this.outputDevice));