MM_MCINOTIFY

This message is sent to a window to notify an application that an MCI device has completed an operation. MCI devices send this message only when the MCI_NOTIFY flag is used with an MCI command message or when the notify flag is used with an MCI command string.

Returns zero if successful. Otherwise, it returns an MCI error code.

UINT wParam

Contains one of the following message:

MCI_NOTIFY_ABORTED	Specifies that the device received a command that prevented the current conditions for initiating the callback from being met. If a new command interrupts the current command and it also requests notification, the device will send only this message and not MCI_NOTIFY_SUPERSEDED.
MCI_NOTIFY_SUCCESSFUL	Specifies that the conditions initiating the callback have been met.
MCI_NOTIFY_SUPERSEDED	Specifies that the device received another command with the MCI_NOTIFY flag set and the current conditions for initiating the callback have been superseded.
MCI_NOTIFY_FAILURE	Specifies that a device error occurred while the device was executing the command.

LPARAM lParam

The low-order word specifies the ID of the device initiating the callback.

A device returns the flag MCI_NOTIFY_SUCCESSFUL with MM_MCINOTIFY when the action for a command finishes. For example, a CD audio device uses this flag for notification for MCI_PLAY when the device finishes playing. The MCI_PLAY command completes successfully only when it reaches the specified end position or reaches the end of the media. Similarly, MCI_SEEK and MCI_RECORD do not return MCI_NOTIFY_SUCCESSFUL until they reach the specified end position or reach the end of the media.

A device returns the flag MCI_NOTIFY_ABORTED with MM_MCINOTIFY only when it receives a command that prevents it from meeting the notification conditions. For example, the command MCI_PLAY would not abort notification for a previous play command provided that the new command does not change the play direction or change the ending position for the play command with an active notify. The MCI_RECORD and MCI_SEEK commands behave similarly.

MCI also does not send MCI_NOTIFY_ABORTED when MCI_PLAY or MCI_RECORD is paused with MCI_PAUSE. Sending the MCI_RESUME command will let them continue to meet the callback conditions.

When your application requests notification for a command, check the error return of mciSendMessage or mciSendCommand. If these functions encounter an error and return a nonzero value, MCI will not set notification for the command.