meta: Add visualization support

This should have an insignificant impact on performance, so it doesn't
hurt to have the option to run a visualizer with ncmpcpp or other
applications.

mpd/.config/mpd/mpd.conf

@@ -13,4 +13,11 @@ audio_output {
   name "PipeWire Sound Server"
 }
 
+audio_output {
+    type                    "fifo"
+    name                    "my_fifo"
+    path                    "/tmp/mpd.fifo"
+    format                  "44100:16:2"
+}
+
 auto_update "yes"

ncmpcpp/.config/ncmpcpp/config

@@ -21,3 +21,10 @@ allow_for_physical_item_deletion = "no"
 mouse_support = "no"
 
 execute_on_song_change = "~/.config/mpd/mpdnotify"
+
+# Visualizer support
+visualizer_data_source = "/tmp/mpd.fifo"
+visualizer_output_name = "my_fifo"
+visualizer_in_stereo = "yes"
+visualizer_type = "spectrum"
+visualizer_look = "+|"