MCI Functions that Call DriverProc

MCI calls the entry point DriverProc in response to the mciSendCommand or mciSendString functions. With the exception of system messages (MCI_SOUND, MCI_BREAK, and MCI_SYSINFO) and the MCI_OPEN and MCI_CLOSE messages, MCI sends the mciSendCommand parameters directly to DriverProc.

For mciSendString, MCI translates the string parameters to parameters used by DriverProc. MCI uses the information stored in the MCI command tables to convert MCI command strings to MCI command messages.