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4/8/2010

This function cleans up the preparation performed by waveOutPrepareHeader. The function must be called after the device driver is finished with a data block. You must call this function before freeing the data buffer.

Syntax 

MMRESULT waveOutUnprepareHeader(
  HWAVEOUT 
hwo, 
  LPWAVEHDR 
pwh, 
  UINT 
cbwh 
);

Parameters

hwo

Handle to the waveform-audio output device.

pwh

Pointer to a WAVEHDRstructure identifying the data block to be cleaned up.

cbwh

Size, in bytes, of the WAVEHDRstructure.

Return Value

One of the values described in the following table is returned.

Value Description

MMSYSERR_NOERROR

Success.

MMSYSERR_INVALHANDLE

Specified device handle is invalid.

MMSYSERR_NODRIVER

No device driver is present.

MMSYSERR_NOMEM

Unable to allocate or lock memory.

WAVERR_STILLPLAYING

Data block pointed to by the pwhparameter is still in the queue.

Remarks

This function complements waveOutPrepareHeader. You must call this function before freeing the buffer. After passing a buffer to the device driver with the waveOutWritefunction, 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.

Requirements

Header mmsystem.h
Library coredll.lib
Windows Embedded CE Windows CE 2.0 and later
Windows Mobile Windows Mobile Version 5.0 and later

See Also