midiInUnprepareHeader function
The midiInUnprepareHeader function cleans up the preparation performed by the midiInPrepareHeader function.
Syntax
MMRESULT midiInUnprepareHeader(
HMIDIIN hMidiIn,
LPMIDIHDR lpMidiInHdr,
UINT cbMidiInHdr
);
Parameters
hMidiIn
Handle to the MIDI input device.lpMidiInHdr
Pointer to a MIDIHDR structure identifying the buffer to be cleaned up.cbMidiInHdr
Size of the MIDIHDR structure.
Return value
Returns MMSYSERR_NOERROR if successful or an error otherwise. Possible error values include the following.
| Return code | Description |
|---|---|
| MIDIERR_STILLPLAYING | The buffer pointed to by lpMidiInHdr is still in the queue. |
| MMSYSERR_INVALPARAM | The specified pointer or structure is invalid. |
| MMSYSERR_INVALHANDLE | The specified device handle is invalid. |
Remarks
This function is complementary to midiInPrepareHeader. You must use this function before freeing the buffer. After passing a buffer to the device driver by using the midiInAddBuffer function, you must wait until the driver is finished with the buffer before using midiInUnprepareHeader. Unpreparing a buffer that has not been prepared has no effect, and the function returns MMSYSERR_NOERROR.
Requirements
Minimum supported client |
Windows 2000 Professional [desktop apps only] |
Minimum supported server |
Windows 2000 Server [desktop apps only] |
Header |
Mmsystem.h (include Windows.h) |
Library |
Winmm.lib |
DLL |
Winmm.dll |