This message is sent to a MIDI input callback function when an input buffer has been filled with MIDI system-exclusive data and is being returned to the application.
DWORD dwParam1
Specifies a far pointer to a MIDIHDR structure identifying the input buffer.
DWORD dwParam2
Specifies the time that the data was received by the input device driver. The timestamp is specified in milliseconds, beginning at 0 when midiInStart was called.
None
The returned buffer may not be full. The dwBytesRecorded field of the MIDIHDR structure specified by dwParam1 will specify the number of bytes recorded into the buffer.
MIM_DATA, MM_MIM_LONGDATA