The MIDIHDR structure defines the header used to identify a MIDI system-exclusive data buffer.
typedef struct midihdr_tag {
LPSTR lpData;
DWORD dwBufferLength;
DWORD dwBytesRecorded;
DWORD dwUser;
DWORD dwFlags;
struct midihdr_tag far * lpNext;
DWORD reserved;
} MIDIHDR;
The MIDIHDR structure has the following fields:
lpData
Specifies a far pointer to the system-exclusive data buffer.
dwBufferLength
Specifies the length of the data buffer.
dwBytesRecorded
When the header is used in input, this specifies how much data is in the buffer.
dwUser
Specifies user data.
dwFlags
Specifies flags giving information about the data buffer.
MHDR_DONE
Set by the device driver to indicate that it is finished with the data buffer and is returning it to the application.
MHDR_PREPARED
Set by Windows to indicate that the data buffer has been prepared with midiInPrepareHeader or midiOutPrepareHeader.
lpNext
Is reserved and should not be used.
reserved
Is reserved and should not be used.