when rendering, use dummy Audio/MIDI devices

include/Mixer.h

@@ -157,7 +157,7 @@ public:
 		}
 	} ;
 
-	void initDevices();
+	void initDevices( bool renderOnly );
 	void clear();
 
 

src/core/Engine.cpp

@@ -70,7 +70,7 @@ void LmmsCore::init( bool renderOnly )
 	s_projectJournal->setJournalling( true );
 
 	emit engine->initProgress(tr("Opening audio and midi devices"));
-	s_mixer->initDevices();
+	s_mixer->initDevices( renderOnly );
 
 	PresetPreviewPlayHandle::init();
 	s_dummyTC = new DummyTrackContainer;

src/core/Mixer.cpp

@@ -203,10 +203,18 @@ Mixer::~Mixer()
 
 
 
-void Mixer::initDevices()
+void Mixer::initDevices( bool renderOnly )
 {
-	m_audioDev = tryAudioDevices();
-	m_midiClient = tryMidiClients();
+	bool success_ful = false;
+	if( renderOnly ) {
+		m_audioDev = new AudioDummy( success_ful, this );
+		m_audioDevName = AudioDummy::name();
+		m_midiClient = new MidiDummy;
+		m_midiClientName = MidiDummy::name();
+	} else {
+		m_audioDev = tryAudioDevices();
+		m_midiClient = tryMidiClients();
+	}
 }