waveOutPrepareHeader

This function prepares a waveform data block for playback.

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

Parameters

  • hwo
    Handle to the waveform-audio output device.
  • pwh
    Pointer to a WAVEHDR structure that identifies the data block to be prepared.
  • cbwh
    Size, in bytes, of the WAVEHDR structure.

Return Values

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.

Remarks

The lpData, dwBufferLength, and dwFlags members of the WAVEHDR structure must be set before calling this function (dwFlags must be zero).

The dwFlags, dwBufferLength, and dwLoops members of the WAVEHDR structure can change between calls to this function and the waveOutWrite function. (The only flags that can change in this interval for the dwFlags member are WHDR_BEGINLOOP and WHDR_ENDLOOP.) If you change the size specified by dwBufferLength before the call to waveOutWrite, the new value must be less than the prepared value.

Preparing a header that has already been prepared has no effect, and the function returns zero.

Requirements

Runs on Versions Defined in Include Link to
Windows CE OS 2.0 and later Mmsystem.h   Wavelib.lib

Note   This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.

 Last updated on Tuesday, July 13, 2004

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