The midiOutPrepareHeader function prepares a MIDI system-exclusive or stream buffer for output.
MMRESULT midiOutPrepareHeader(
HMIDIOUT hmo,
LPMIDIHDR lpMidiOutHdr,
UINT cbMidiOutHdr
);
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 or the given stream buffer is greater than 64K. |
MMSYSERR_NOMEM | The system is unable to allocate or lock memory. |
A stream buffer cannot be larger than 64K.
Preparing a header that has already been prepared has no effect, and the function returns MMSYSERR_NOERROR.
After the header has been prepared, do not modify the buffer. To free the buffer, use the midiOutUnprepareHeader 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.
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.
Musical Instrument Digital Interface (MIDI) Overview, MIDI Functions, MIDIHDR, midiOutUnprepareHeader