Toggle the fifo output once if synchronization is disabled

src/screens/visualizer.cpp

@@ -112,7 +112,8 @@ void Visualizer::switchTo()
 	SwitchTo::execute(this);
 	w.clear();
 	SetFD();
-	m_timer = boost::posix_time::from_time_t(0);
+	// negative infinity to toggle output in update() at least once
+	m_timer = boost::posix_time::neg_infin;
 	drawHeader();
 	memset(m_sample_buffer.data(), 0, m_sample_buffer.size()*sizeof(int16_t));
 #	ifdef HAVE_FFTW3_H
@@ -160,15 +161,12 @@ void Visualizer::update()
 		memcpy(sdata_end - data, temp_sdata, data);
 	}
 
-	if (Config.visualizer_sync_interval > boost::posix_time::seconds(0))
+	if (m_output_id != -1 && Global::Timer - m_timer > Config.visualizer_sync_interval)
 	{
-		if (m_output_id != -1 && Global::Timer - m_timer > Config.visualizer_sync_interval)
+		Mpd.DisableOutput(m_output_id);
-		{
+		usleep(50000);
-			Mpd.DisableOutput(m_output_id);
+		Mpd.EnableOutput(m_output_id);
-			usleep(50000);
+		m_timer = Global::Timer;
-			Mpd.EnableOutput(m_output_id);
-			m_timer = Global::Timer;
-		}
 	}
 
 	void (Visualizer::*draw)(int16_t *, ssize_t, size_t, size_t);

src/settings.cpp

@@ -282,8 +282,9 @@ bool Configuration::read(const std::vector<std::string> &config_paths, bool igno
 	p.add("visualizer_sync_interval", &visualizer_sync_interval, "0",
 	      [](std::string v) {
 		      unsigned sync_interval = verbose_lexical_cast<unsigned>(v);
-		      if (sync_interval > 0)
+		      if (sync_interval == 0)
-			      lowerBoundCheck<unsigned>(sync_interval, 10);
+			      sync_interval = std::numeric_limits<unsigned>::max();
+		      lowerBoundCheck<unsigned>(sync_interval, 10);
 		      return boost::posix_time::seconds(sync_interval);
 	});
 	p.add("visualizer_type", &visualizer_type, "wave");