add levels example

examples/levels/main.rb

@@ -0,0 +1,53 @@
+require "obsws"
+require "perfect_toml"
+
+OBSWS::LOGGER.info!
+DEVICE = "Desktop Audio"
+
+module LevelTypes
+  VU = 0
+  POSTFADER = 1
+  PREFADER = 2
+end
+
+class Observer
+  attr_reader :running
+
+  def initialize(**kwargs)
+    kwargs[:subs] = OBSWS::Events::SUBS::LOW_VOLUME | OBSWS::Events::SUBS::INPUTVOLUMEMETERS
+    @e_client = OBSWS::Events::Client.new(**kwargs)
+    @e_client.add_observer(self)
+  end
+  
+  def on_input_mute_state_changed(data)
+    """An input's mute state has changed."""
+    if data.input_name == DEVICE
+      puts "#{DEVICE} mute toggled"
+    end
+  end
+
+  def on_input_volume_meters(data)
+    def fget(x) = x > 0 ? (20 * Math.log(x, 10)).round(1) : -200.0
+
+    data.inputs.each do |d|
+      name = d[:inputName]
+      if name == DEVICE && !d[:inputLevelsMul].empty?
+        left, right = d[:inputLevelsMul]
+        puts "#{name} [L: #{fget(left[LevelTypes::POSTFADER])}, R: #{fget(right[LevelTypes::POSTFADER])}]"
+      end
+    end
+  end
+end
+
+def conn_from_toml
+  PerfectTOML.load_file("obs.toml", symbolize_names: true)[:connection]
+end
+
+def main
+  o = Observer.new(**conn_from_toml)
+
+  puts "press <Enter> to quit"
+  loop { exit if gets.chomp.empty? }
+end
+
+main if $0 == __FILE__