dwFlags = (DWORD) lParam1; // MCI flags lpMCI_OPEN_PARMS = (LPMCI_OPEN_PARMS) lParam2; // Pointer to MCI_OPEN_PARMS // structure.
This message is the version of the MCI_OPEN command sent by MCI to an MCI device.
lParam1
Contains the flags specified in the MCI_OPEN message.
lParam2
Specifies a far pointer to the MCI_OPEN_PARMS structure. This structure contains the information passed by the MCI_OPEN call from the application.
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.