This MCI command message freezes motion on the display. This command is part of the video overlay command set. The parameters and flags for this message vary according to the selected device.
DWORD lParam1
The following flags apply to all devices supporting MCI_FREEZE:
MCI_NOTIFY
Specifies that MCI should post the MM_MCINOTIFY message when this command completes. The window to receive this message is specified in the dwCallback field of the data structure identified by lpFreeze.
MCI_WAIT
Specifies that the freeze operation should finish before MCI returns control to the application.
MCI_OVLY_RECT
Specifies that the rc field of the data structure identified by lpFreeze contains a valid rectangle. If this flag is not specified, the device driver will freeze the entire frame.
LPMCI_OVLY_RECT_PARMS lParam2
Specifies a far pointer to a MCI_OVLY_RECT_PARMS data structure. (Devices with additional parameters might replace this data structure with a device-specific data structure.)
Returns zero if successful. Otherwise, it returns an MCI error code.