The MIM_LONGDATA message is sent to a MIDI input callback function when a system-exclusive buffer has been filled with data and is being returned to the application.
MIM_LONGDATA dwParam1= (DWORD) lpMidiHdr dwParam2= dwTimestamp
Pointer to a MIDIHDR structure identifying the input buffer.
Time that the data was received by the input device driver. The time stamp is specified in milliseconds, beginning at zero when the midiInStart function was called.
This message does not return a value.
The returned buffer might not be full. To determine the number of bytes recorded into the returned buffer, use the dwBytesRecorded member of the MIDIHDR structure specified by lpMidiHdr.
** Windows NT/2000/XP:** Included in Windows NT 3.1 and later.
** Windows 95/98/Me:** Included in Windows 95 and later.
** Header:** Declared in Mmsystem.h; include Windows.h.