waveOutUnprepareHeader.md

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Function name : waveOutUnprepareHeader

Group: Windows Multimedia - Library: winmm

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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.

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Code examples:

WAV file player
Playing WAV sounds simultaneously

Declaration:

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

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FoxPro declaration:

DECLARE INTEGER waveOutUnprepareHeader IN winmm;
	INTEGER   hwi,;
	STRING  @ pwh,;
	INTEGER   cbwh
  

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Parameters:

hwo Handle to the waveform-audio output device.

pwh Pointer to a WAVEHDR structure identifying the data block to be cleaned up.

cbwh Size, in bytes, of the WAVEHDR structure.

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Return value:

Returns MMSYSERR_NOERROR (0) if successful or an error otherwise.

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Comments:

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.

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