This message is the version of the MCI_OPEN command sent by MCI to an MCI device.
DWORD lParam1
Contains the flags specified in the MCI_OPEN message.
LPMCI_OPEN_PARMS lParam2
Specifies a far pointer to the MCI_OPEN_PARMS data structure. This structure contains the information passed by the MCI_OPEN call from the application.
Returns zero if successful. Otherwise, it returns an MCI error code.
An MCI internal procedure intercepts the MCI_OPEN message sent by an application. After processing, the procedure calls the device with DRV_OPEN and MCI_OPEN_DRIVER.