midiInPrepareHeader

The midiInPrepareHeader function prepares a buffer for MIDI input.

MMRESULT midiInPrepareHeader(
  HMIDIIN hMidiIn,        
  LPMIDIHDR lpMidiInHdr,  
  UINT cbMidiInHdr        
);

Parameters

hMidiIn
Handle of the MIDI input device.
lpMidiInHdr
Address of a MIDIHDR structure that identifies the buffer to be prepared.
cbMidiInHdr
Size, in bytes, of the MIDIHDR structure.

Return Values

Returns MMSYSERR_NOERROR if successful or an error otherwise. Possible error values include the following:

Value Description
MMSYSERR_INVALHANDLE The specified device handle is invalid.
MMSYSERR_INVALPARAM The specified address is invalid.
MMSYSERR_NOMEM The system is unable to allocate or lock memory.

Remarks

Preparing a header that has already been prepared has no effect, and the function returns zero.

After the header has been prepared, do not modify the buffer. To free the buffer, use the midiInUnprepareHeader function.

Before using this function, you must set the lpData, dwBufferLength, and dwFlags members of the MIDIHDR structure. The dwFlags member must be set to zero.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in mmsystem.h.
  Import Library: Use winmm.lib.

See Also

Musical Instrument Digital Interface (MIDI) Overview, MIDI Functions, MIDIHDR, midiInUnprepareHeader