provide a way to sync between visualization and sound

workaround for http://musicpd.org/mantis/view.php?id=2503

doc/config

@@ -35,6 +35,16 @@
 #visualizer_fifo_path = ""
 #
 ##
+## Note: Below parameter is needed for ncmpcpp
+## to determine which output provides data for
+## visualizer and thus allow syncing between
+## visualization and sound as currently there
+## are some problems with it.
+##
+#
+#visualizer_output_name = ""
+#
+##
 ## Note: To enable spectrum frequency visualization
 ## you need to compile ncmpcpp with fftw3 support.
 ##

doc/ncmpcpp.1

@@ -70,6 +70,9 @@ Set connection timeout to MPD to given value.
 Default number of seconds to crossfade, if enabled by ncmpcpp.
 .TP
 .B visualizer_fifo_path = PATH
+Name of output that provides data for visualizer. Needed to keep sound and visualization in sync.
+.TP
+.B visualizer_output_name = NAME
 Path to mpd fifo output. This is needed to make music visualizer work (note that output sound format of this fifo has to be 44100:16:1)
 .TP
 .B visualizer_type = spectrum/wave

src/settings.cpp

@@ -521,11 +521,16 @@ void ReadConfiguration(ncmpcpp_config &conf)
 					conf.mpd_music_dir = v + "/";
 				}
 			}
-			if (cl.find("visualizer_fifo_path") != std::string::npos)
+			else if (cl.find("visualizer_fifo_path") != std::string::npos)
 			{
 				if (!v.empty())
 					conf.visualizer_fifo_path = v;
 			}
+			else if (cl.find("visualizer_output_name") != std::string::npos)
+			{
+				if (!v.empty())
+					conf.visualizer_output_name = v;
+			}
 			else if (cl.find("mpd_port") != std::string::npos)
 			{
 				if (StrToInt(v))

src/settings.h

@@ -131,6 +131,7 @@ struct ncmpcpp_config
 	std::string mpd_host;
 	std::string mpd_music_dir;
 	std::string visualizer_fifo_path;
+	std::string visualizer_output_name;
 	std::string empty_tag;
 	std::string song_list_columns_format;
 	std::string song_list_format;

src/visualizer.cpp

@@ -29,6 +29,7 @@
 #include <cstring>
 #include <fstream>
 #include <fcntl.h>
+#include <sys/time.h>
 
 using Global::myScreen;
 using Global::MainStartY;
@@ -53,6 +54,18 @@ void Visualizer::Init()
 	itsPlan = fftw_plan_dft_r2c_1d(Samples, itsInput, itsOutput, FFTW_ESTIMATE);
 #	endif // HAVE_FFTW3_H
 	
+	itsOutputID = -1;
+	if (!Config.visualizer_output_name.empty())
+	{
+		MPD::OutputList outputs;
+		Mpd.GetOutputs(outputs);
+		for (unsigned i = 0; i < outputs.size(); ++i)
+			if (outputs[i].first == Config.visualizer_output_name)
+				itsOutputID = i;
+		if (itsOutputID == -1)
+			ShowMessage("There is no output named \"%s\"!", Config.visualizer_output_name.c_str());
+	}
+	
 	isInitialized = 1;
 }
 
@@ -72,6 +85,9 @@ void Visualizer::SwitchTo()
 	
 	SetFD();
 	
+	itsTimer.tv_sec = 0;
+	itsTimer.tv_usec = 0;
+	
 	if (itsFifo >= 0)
 		Global::wFooter->SetTimeout(1000/25);
 	Global::RedrawHeader = 1;
@@ -101,6 +117,13 @@ void Visualizer::Update()
 		return;
 	}
 	
+	if (itsOutputID != -1 && Global::Timer.tv_sec > itsTimer.tv_sec+5)
+	{
+		Mpd.DisableOutput(itsOutputID);
+		Mpd.EnableOutput(itsOutputID);
+		gettimeofday(&itsTimer, 0);
+	}
+	
 	// it supports only PCM in format 44100:16:1
 	static int16_t buf[Samples];
 	ssize_t data = read(itsFifo, buf, sizeof(buf));

src/visualizer.h

@@ -65,6 +65,9 @@ class Visualizer : public Screen<Window>
 		void DrawFrequencySpectrum(int16_t *, ssize_t);
 #		endif // HAVE_FFTW3_H
 		
+		int itsOutputID;
+		timeval itsTimer;
+		
 		int itsFifo;
 #		ifdef HAVE_FFTW3_H
 		unsigned *itsFreqsMagnitude;