add visualizer_sample_multiplier config option

doc/bindings

@@ -439,6 +439,9 @@
 #def_key "m"
 #  toggle_media_library_sort_mode
 #
+#def_key "m"
+#  set_visualizer_sample_multiplier
+#
 #def_key "n"
 #  move_sort_order_down
 #

doc/config

@@ -70,6 +70,12 @@
 #visualizer_in_stereo = yes
 #
 ##
+## Multiply received samples by given value. Very
+## useful for proper visualization of quiet music.
+##
+#visualizer_sample_multipler = 1
+#
+##
 ## Note: Below parameter defines how often ncmpcpp
 ## has to "synchronize" visualizer and audio outputs.
 ## 30 seconds is optimal value, but if you experience

doc/ncmpcpp.1

@@ -66,6 +66,9 @@ Path to mpd fifo output. This is needed to make music visualizer work (note that
 .B visualizer_output_name = NAME
 Name of output that provides data for visualizer. Needed to keep sound and visualization in sync.
 .TP
+.B visualizer_sample_multiplier = NUMBER
+Multiply received samples by given value. Very useful for proper visualization of quiet music.
+.TP
 .B visualizer_sync_interval = SECONDS
 Defines interval between syncing visualizer and audio outputs.
 .TP

src/actions.cpp

@@ -2184,6 +2184,31 @@ void SetSelectedItemsPriority::run()
 	myPlaylist->SetSelectedItemsPriority(prio);
 }
 
+bool SetVisualizerSampleMultiplier::canBeRun() const
+{
+#	ifdef ENABLE_VISUALIZER
+	return myScreen == myVisualizer;
+#	else
+	return false;
+#	endif // ENABLE_VISUALIZER
+}
+
+void SetVisualizerSampleMultiplier::run()
+{
+#	ifdef ENABLE_VISUALIZER
+	using Global::wFooter;
+
+	Statusbar::lock();
+	Statusbar::put() << "Set visualizer sample multiplier: ";
+	std::string smultiplier = wFooter->getString();
+	Statusbar::unlock();
+
+	double multiplier = fromString<double>(smultiplier);
+	lowerBoundCheck(multiplier, 1.0);
+	Config.visualizer_sample_multiplier = multiplier;
+#	endif // ENABLE_VISUALIZER
+}
+
 bool FilterPlaylistOnPriorities::canBeRun() const
 {
 	return myScreen == myPlaylist;
@@ -2612,6 +2637,7 @@ void populateActions()
 	insert_action(new Actions::ToggleMediaLibrarySortMode());
 	insert_action(new Actions::RefetchLyrics());
 	insert_action(new Actions::SetSelectedItemsPriority());
+	insert_action(new Actions::SetVisualizerSampleMultiplier());
 	insert_action(new Actions::FilterPlaylistOnPriorities());
 	insert_action(new Actions::ShowSongInfo());
 	insert_action(new Actions::ShowArtistInfo());

src/actions.h

@@ -52,9 +52,9 @@ enum class Type
 	ToggleSpaceMode, ToggleAddMode, ToggleMouse, ToggleBitrateVisibility,
 	AddRandomItems, ToggleBrowserSortMode, ToggleLibraryTagType,
 	ToggleMediaLibrarySortMode, RefetchLyrics,
-	SetSelectedItemsPriority, FilterPlaylistOnPriorities, ShowSongInfo,
+	SetSelectedItemsPriority, SetVisualizerSampleMultiplier, FilterPlaylistOnPriorities,
-	ShowArtistInfo, ShowLyrics, Quit, NextScreen, PreviousScreen, ShowHelp,
+	ShowSongInfo, ShowArtistInfo, ShowLyrics, Quit, NextScreen, PreviousScreen,
-	ShowPlaylist, ShowBrowser, ChangeBrowseMode, ShowSearchEngine,
+	ShowHelp, ShowPlaylist, ShowBrowser, ChangeBrowseMode, ShowSearchEngine,
 	ResetSearchEngine, ShowMediaLibrary, ToggleMediaLibraryColumnsMode,
 	ShowPlaylistEditor, ShowTagEditor, ShowOutputs, ShowVisualizer,
 	ShowClock, ShowServerInfo,
@@ -959,6 +959,16 @@ protected:
 	virtual void run();
 };
 
+struct SetVisualizerSampleMultiplier : public BaseAction
+{
+	SetVisualizerSampleMultiplier()
+	: BaseAction(Type::SetVisualizerSampleMultiplier, "set_visualizer_sample_multiplier") { }
+
+protected:
+	virtual bool canBeRun() const;
+	virtual void run();
+};
+
 struct FilterPlaylistOnPriorities : public BaseAction
 {
 	FilterPlaylistOnPriorities()

src/bindings.cpp

@@ -540,6 +540,7 @@ void BindingsConfiguration::generateDefaults()
 		bind(k, Actions::Type::MoveSortOrderUp);
 		bind(k, Actions::Type::MoveSelectedItemsUp);
 		bind(k, Actions::Type::ToggleMediaLibrarySortMode);
+		bind(k, Actions::Type::SetVisualizerSampleMultiplier);
 	}
 	if (notBound(k = stringToKey("n")))
 	{

src/help.cpp

@@ -374,6 +374,7 @@ void write_bindings(NC::Scrollpad &w)
 #	if defined(ENABLE_VISUALIZER) && defined(HAVE_FFTW3_H)
 	key_section(w, "Music visualizer");
 	key(w, Type::PressSpace, "Toggle visualization type");
+	key(w, Type::SetVisualizerSampleMultiplier, "Set visualizer sample multiplier");
 #	endif // ENABLE_VISUALIZER && HAVE_FFTW3_H
 
 	mouse_section(w, "Global");

src/settings.cpp

@@ -221,6 +221,11 @@ bool Configuration::read(const std::string &config_path)
 	p.add("visualizer_in_stereo", yes_no(
 		visualizer_in_stereo, true
 	));
+	p.add("visualizer_sample_multiplier", assign_default<double>(
+		visualizer_sample_multiplier, 1.0, [](double v) {
+			lowerBoundCheck(v, 1.0);
+			return v;
+	}));
 	p.add("visualizer_sync_interval", assign_default<unsigned>(
 		visualizer_sync_interval, 30, [](unsigned v) {
 			return boost::posix_time::seconds(v);

src/settings.h

@@ -176,6 +176,7 @@ struct Configuration
 	boost::posix_time::seconds playlist_disable_highlight_delay;
 	boost::posix_time::seconds visualizer_sync_interval;
 	
+	double visualizer_sample_multiplier;
 	double locked_screen_width_part;
 	
 	size_t selected_item_prefix_length;

src/visualizer.cpp

@@ -113,9 +113,19 @@ void Visualizer::update()
 	else
 #	endif // HAVE_FFTW3_H
 		draw = &Visualizer::DrawSoundWave;
-	
+
+	const ssize_t samples_read = data/sizeof(int16_t);
+	std::for_each(buf, buf+samples_read, [](int16_t &sample) {
+		int32_t tmp = sample * Config.visualizer_sample_multiplier;
+		if (tmp < std::numeric_limits<int16_t>::min())
+			sample = std::numeric_limits<int16_t>::min();
+		else if (tmp > std::numeric_limits<int16_t>::max())
+			sample = std::numeric_limits<int16_t>::max();
+		else
+			sample = tmp;
+	});
+
 	w.clear();
-	ssize_t samples_read = data/sizeof(int16_t);
 	if (Config.visualizer_in_stereo)
 	{
 		int16_t buf_left[samples_read/2], buf_right[samples_read/2];