This
parameter can contain any of the following flags:
MCI_NOTIFY
A notification message will be posted
to the window specified in the hwndCallback parameter of the data
structure pointed to by the pParam2 parameter. The notification
will be posted when the action indicated by this message is completed or
when an error occurs.
MCI_WAIT
Control
is not to be returned until the action indicated by this message is completed
or an error occurs.
Video Overlay Extensions
MCI_OVLY_FREEZE_RECT
The rect field of the
data structure identified by pParam2 contains a valid rectangle.
If the MCI_OVLY_FREEZE_RECT parameter is not specified, the entire video
destination rectangle is unfrozen.
MCI_OVLY_FREEZE_RECT_OUTSIDE
Indicates the area outside the specified rectangle
is to be unfrozen.