osd.icon( type, [id] ): Display an icon on the given OSD channel. Uses the
default channel is none is given. Icon types are: "pause", "play",
"speaker" and "mute".
-osd.message( string, [id] ): Display text message on the given OSD channel.
+osd.message( string, [id], [position], [duration]: Display the text message on
+ the given OSD channel. Position types are: "center", "left", "right", "top",
+ "bottom", "top-left", "top-right", "bottom-left" or "bottom-right". The
+ duration is set in microseconds.
osd.slider( position, type, [id] ): Display slider. Position is an integer
from 0 to 100. Type can be "horizontal" or "vertical".
osd.channel_register(): Register a new OSD channel. Returns the channel id.