The MM_MOM_POSITIONCB message is sent to a window when an MEVT_F_CALLBACK event is reached in the MIDI output stream.
MM_MOM_POSITIONCB wParam = (WPARAM) lpMidiHdr lParam = reserved
Pointer to a MIDIHDR structure that identifies the event that caused the callback. The dwOffset member gives the offset of the event.
Reserved; do not use.
This message does not return a value.
Playback of the stream buffer continues even while the callback function is executing. Any events after the MEVT_F_CALLBACK event in the buffer will be scheduled and sent on time regardless of how much time is spent in the callback function.
If position callbacks are being generated more quickly than your application can process them, the dwOffset member of the MIDIHDR structure might refer to an event your application has not yet processed.
|Minimum supported client
||Windows 2000 Professional [desktop apps only]
|Minimum supported server
||Windows 2000 Server [desktop apps only]