WAVEHDR

This structure defines the header used to identify a waveform-audio buffer.

typedef struct {
LPSTR lpData;
DWORD dwBufferLength;
DWORD dwBytesRecorded;
DWORD dwUser;
DWORD dwFlags;
DWORD dwLoops;
struct wavehdr_tag *lpNext;
DWORD reserved;}
WAVEHDR;

Members

  • lpData
    Long pointer to the address of the waveform buffer.

  • dwBufferLength
    Specifies the length, in bytes, of the buffer.

  • dwBytesRecorded
    When the header is used in input, this member specifies how much data is in the buffer.

  • dwUser
    Specifies user data.

  • dwFlags
    Specifies information about the buffer. It is one of the following flags:

    Value Description
    WHDR_BEGINLOOP This buffer is the first buffer in a loop. This flag is used only with output buffers.
    WHDR_DONE Set by the device driver to indicate that it is finished with the buffer and is returning it to the application.
    WHDR_ENDLOOP This buffer is the last buffer in a loop. This flag is used only with output buffers.
    WHDR_INQUEUE Set by Windows to indicate that the buffer is queued for playback.
    WHDR_PREPARED Set by Windows to indicate that the buffer has been prepared with the waveInPrepareHeader or waveOutPrepareHeader function.
  • dwLoops
    Specifies the number of times to play the loop. This member is used only with output buffers.

  • lpNext
    Reserved.

  • reserved
    Reserved.

Remarks

Use the WHDR_BEGINLOOP and WHDR_ENDLOOP flags in the dwFlags member to specify the beginning and ending data blocks for looping. To loop on a single block, specify both flags for the same block. Use the dwLoops member in the WAVEHDR structure for the first block in the loop to specify the number of times to play the loop.

The lpData, dwBufferLength, and dwFlags members must be set before calling the waveInPrepareHeader or waveOutPrepareHeader function. For either function, the dwFlags member must be set to zero.

Requirements

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

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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