Use media-title instead of filename for window title

uosc.lua

@@ -244,7 +244,7 @@ local state = {
 		return 'linux'
 	end)(),
 	cwd = mp.get_property('working-directory'),
-	filename = '',
+	media_title = '',
 	border = mp.get_property_native('border'),
 	duration = nil,
 	position = nil,
@@ -1413,7 +1413,7 @@ function render_window_controls(this)
 	ass:draw_stop()
 
 	-- Window title
-	if options.title then
+	if options.title and state.media_title then
 		local spacing = math.ceil(config.window_controls.height * 0.25)
 		local fontsize = math.floor(config.window_controls.height - (spacing * 2))
 		local clip_coordinates = '0,0,'..(minimize.ax - spacing)..','..config.window_controls.height
@@ -1423,7 +1423,7 @@ function render_window_controls(this)
 		ass:append(ass_opacity(1, opacity))
 		ass:pos(0 + spacing, config.window_controls.height / 2)
 		ass:an(4)
-		ass:append(state.filename)
+		ass:append(state.media_title)
 	end
 
 	return ass
@@ -2256,12 +2256,9 @@ options.subtitle_types = split(options.subtitle_types, ' *, *')
 
 -- HOOKS
 
-mp.register_event('file-loaded', function()
-	state.duration = mp.get_property_number('duration', nil)
-	state.filename = mp.get_property_osd('filename', '')
-end)
-
 mp.observe_property('chapter-list', 'native', parse_chapters)
+mp.observe_property('duration', 'number', create_state_setter('duration'))
+mp.observe_property('media-title', 'string', create_state_setter('media_title'))
 mp.observe_property('fullscreen', 'bool', create_state_setter('fullscreen'))
 mp.observe_property('window-maximized', 'bool', create_state_setter('maximized'))
 mp.observe_property('idle-active', 'bool', create_state_setter('idle'))