possible value are h or v.
If set, displays volume values. Default is enabled.
@item o
If set, displays volume values. Default is enabled.
@item o
-Set orientation, can be @code{horizontal} or @code{vertical},
-default is @code{horizontal}.
+Set orientation, can be horizontal: @code{h} or vertical: @code{v},
+default is @code{h}.
@item s
Set step size, allowed range is [0, 5]. Default is 0, which means
@item s
Set step size, allowed range is [0, 5]. Default is 0, which means