The waveOutUnprepareHeader function cleans up the preparation performed by the waveOutPrepareHeader function. This function must be called after the device driver is finished with a data block. You must call this function before freeing the buffer.
MMRESULT waveOutUnprepareHeader(
HWAVEOUT hwo,
LPWAVEHDR pwh,
UINT cbwh
);
Returns MMSYSERR_NOERROR if successful or an error otherwise. Possible error values include the following:
Value | Description | |
---|---|---|
MMSYSERR_INVALHANDLE | Specified device handle is invalid. | |
MMSYSERR_NODRIVER | No device driver is present. | |
MMSYSERR_NOMEM | Unable to allocate or lock memory. | |
WAVERR_STILLPLAYING | The data block pointed to by the pwh parameter is still in the queue. |
This function complements waveOutPrepareHeader. You must call this function before freeing the buffer. After passing a buffer to the device driver with the waveOutWrite function, you must wait until the driver is finished with the buffer before calling waveOutUnprepareHeader.
Unpreparing a buffer that has not been prepared has no effect, and the function returns zero.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Requires version 2.0 or later.
Header: Declared in mmsystem.h.
Import Library: Use winmm.lib.
Waveform Audio Overview, Waveform Functions, waveOutPrepareHeader, WAVEHDR, waveOutWrite